diff --git a/src/Umbraco.Abstractions/Cache/DictionaryAppCache.cs b/src/Umbraco.Abstractions/Cache/DictionaryAppCache.cs
index fd360b303d..d372916240 100644
--- a/src/Umbraco.Abstractions/Cache/DictionaryAppCache.cs
+++ b/src/Umbraco.Abstractions/Cache/DictionaryAppCache.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Text.RegularExpressions;
@@ -101,5 +102,9 @@ namespace Umbraco.Core.Cache
             var compiled = new Regex(regex, RegexOptions.Compiled);
             _items.RemoveAll(kvp => compiled.IsMatch(kvp.Key));
         }
+
+        public IEnumerator<KeyValuePair<string, object>> GetEnumerator() => _items.GetEnumerator();
+
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
     }
 }
diff --git a/src/Umbraco.Abstractions/Cache/HttpRequestAppCache.cs b/src/Umbraco.Abstractions/Cache/HttpRequestAppCache.cs
index 87d87ad1c9..e698d93ebe 100644
--- a/src/Umbraco.Abstractions/Cache/HttpRequestAppCache.cs
+++ b/src/Umbraco.Abstractions/Cache/HttpRequestAppCache.cs
@@ -171,5 +171,20 @@ namespace Umbraco.Core.Cache
         }
 
         #endregion
+
+        public IEnumerator<KeyValuePair<string, object>> GetEnumerator()
+        {
+            if (!TryGetContextItems(out var items))
+            {
+                yield break;
+            }
+
+            foreach (DictionaryEntry item in items)
+            {
+                yield return new KeyValuePair<string, object>(item.Key.ToString(), item.Value);
+            }
+        }
+
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
     }
 }
diff --git a/src/Umbraco.Abstractions/Cache/IRequestCache.cs b/src/Umbraco.Abstractions/Cache/IRequestCache.cs
index 5ed32b5ba0..7ed7f8251c 100644
--- a/src/Umbraco.Abstractions/Cache/IRequestCache.cs
+++ b/src/Umbraco.Abstractions/Cache/IRequestCache.cs
@@ -1,6 +1,8 @@
+using System.Collections.Generic;
+
 namespace Umbraco.Core.Cache
 {
-    public interface IRequestCache : IAppCache
+    public interface IRequestCache : IAppCache, IEnumerable<KeyValuePair<string, object>>
     {
         bool Set(string key, object value);
         bool Remove(string key);
diff --git a/src/Umbraco.Abstractions/Cache/NoAppCache.cs b/src/Umbraco.Abstractions/Cache/NoAppCache.cs
index 5ca8f47059..60bc6fb8b8 100644
--- a/src/Umbraco.Abstractions/Cache/NoAppCache.cs
+++ b/src/Umbraco.Abstractions/Cache/NoAppCache.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -84,5 +85,9 @@ namespace Umbraco.Core.Cache
         /// <inheritdoc />
         public virtual void ClearByRegex(string regex)
         { }
+
+        public IEnumerator<KeyValuePair<string, object>> GetEnumerator() => new Dictionary<string, object>().GetEnumerator();
+
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
     }
 }
diff --git a/src/Umbraco.Web/HybridAccessorBase.cs b/src/Umbraco.Abstractions/HybridAccessorBase.cs
similarity index 71%
rename from src/Umbraco.Web/HybridAccessorBase.cs
rename to src/Umbraco.Abstractions/HybridAccessorBase.cs
index ec18b6f3d4..3e17f7b757 100644
--- a/src/Umbraco.Web/HybridAccessorBase.cs
+++ b/src/Umbraco.Abstractions/HybridAccessorBase.cs
@@ -1,6 +1,7 @@
 using System;
-using System.Runtime.Remoting.Messaging;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
+using Umbraco.Core.Scoping;
 
 namespace Umbraco.Web
 {
@@ -16,12 +17,14 @@ namespace Umbraco.Web
     public abstract class HybridAccessorBase<T>
         where T : class
     {
+        private readonly IRequestCache _requestCache;
+
         // ReSharper disable StaticMemberInGenericType
         private static readonly object Locker = new object();
         private static bool _registered;
         // ReSharper restore StaticMemberInGenericType
 
-        private readonly IHttpContextAccessor _httpContextAccessor;
+      //  private readonly IHttpContextAccessor _httpContextAccessor;
 
         protected abstract string ItemKey { get; }
 
@@ -42,17 +45,16 @@ namespace Umbraco.Web
         // yes! flows with async!
         private T NonContextValue
         {
-            get => (T) CallContext.LogicalGetData(ItemKey);
+            get => CallContext<T>.GetData(ItemKey);
             set
             {
-                if (value == null) CallContext.FreeNamedDataSlot(ItemKey);
-                else CallContext.LogicalSetData(ItemKey, value);
+                CallContext<T>.SetData(ItemKey, value);
             }
         }
 
-        protected HybridAccessorBase(IHttpContextAccessor httpContextAccessor)
+        protected HybridAccessorBase(IRequestCache requestCache)
         {
-            _httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException(nameof(httpContextAccessor));
+            _requestCache = requestCache ?? throw new ArgumentNullException(nameof(requestCache));
 
             lock (Locker)
             {
@@ -65,15 +67,14 @@ namespace Umbraco.Web
             var itemKey = ItemKey; // virtual
             SafeCallContext.Register(() =>
             {
-                var value = CallContext.LogicalGetData(itemKey);
-                CallContext.FreeNamedDataSlot(itemKey);
+                var value = CallContext<T>.GetData(itemKey);
                 return value;
             }, o =>
             {
                 if (o == null) return;
                 var value = o as T;
                 if (value == null) throw new ArgumentException($"Expected type {typeof(T).FullName}, got {o.GetType().FullName}", nameof(o));
-                CallContext.LogicalSetData(itemKey, value);
+                CallContext<T>.SetData(itemKey, value);
             });
         }
 
@@ -81,20 +82,23 @@ namespace Umbraco.Web
         {
             get
             {
-                var httpContext = _httpContextAccessor.HttpContext;
-                if (httpContext == null) return NonContextValue;
-                return (T) httpContext.Items[ItemKey];
+                if (!_requestCache.IsAvailable)
+                {
+                    return NonContextValue;
+                }
+                return (T) _requestCache.Get(ItemKey);
             }
 
             set
             {
-                var httpContext = _httpContextAccessor.HttpContext;
-                if (httpContext == null)
+                if (!_requestCache.IsAvailable)
+                {
                     NonContextValue = value;
+                }
                 else if (value == null)
-                    httpContext.Items.Remove(ItemKey);
+                    _requestCache.Remove(ItemKey);
                 else
-                    httpContext.Items[ItemKey] = value;
+                    _requestCache.Set(ItemKey, value);
             }
         }
     }
diff --git a/src/Umbraco.Web/HybridEventMessagesAccessor.cs b/src/Umbraco.Abstractions/HybridEventMessagesAccessor.cs
similarity index 70%
rename from src/Umbraco.Web/HybridEventMessagesAccessor.cs
rename to src/Umbraco.Abstractions/HybridEventMessagesAccessor.cs
index fddde403d8..b2700eb137 100644
--- a/src/Umbraco.Web/HybridEventMessagesAccessor.cs
+++ b/src/Umbraco.Abstractions/HybridEventMessagesAccessor.cs
@@ -1,4 +1,5 @@
-using Umbraco.Core.Events;
+using Umbraco.Core.Cache;
+using Umbraco.Core.Events;
 
 namespace Umbraco.Web
 {
@@ -6,8 +7,8 @@ namespace Umbraco.Web
     {
         protected override string ItemKey => "Umbraco.Core.Events.HybridEventMessagesAccessor";
 
-        public HybridEventMessagesAccessor(IHttpContextAccessor httpContextAccessor)
-            : base(httpContextAccessor)
+        public HybridEventMessagesAccessor(IRequestCache requestCache)
+            : base(requestCache)
         { }
 
         public EventMessages EventMessages
diff --git a/src/Umbraco.Web/Models/PublishedContent/HttpContextVariationContextAccessor.cs b/src/Umbraco.Abstractions/Models/PublishedContent/HttpContextVariationContextAccessor.cs
similarity index 50%
rename from src/Umbraco.Web/Models/PublishedContent/HttpContextVariationContextAccessor.cs
rename to src/Umbraco.Abstractions/Models/PublishedContent/HttpContextVariationContextAccessor.cs
index 0007b346c5..41b81a4a6e 100644
--- a/src/Umbraco.Web/Models/PublishedContent/HttpContextVariationContextAccessor.cs
+++ b/src/Umbraco.Abstractions/Models/PublishedContent/HttpContextVariationContextAccessor.cs
@@ -1,4 +1,5 @@
-using Umbraco.Core.Models.PublishedContent;
+using Umbraco.Core.Cache;
+using Umbraco.Core.Models.PublishedContent;
 
 namespace Umbraco.Web.Models.PublishedContent
 {
@@ -7,22 +8,22 @@ namespace Umbraco.Web.Models.PublishedContent
     /// </summary>
     public class HttpContextVariationContextAccessor : IVariationContextAccessor
     {
-        public const string ContextKey = "Umbraco.Web.Models.PublishedContent.DefaultVariationContextAccessor";
-        public readonly IHttpContextAccessor HttpContextAccessor;
+        private readonly IRequestCache _requestCache;
+        private const string _contextKey = "Umbraco.Web.Models.PublishedContent.DefaultVariationContextAccessor";
 
         /// <summary>
         /// Initializes a new instance of the <see cref="HttpContextVariationContextAccessor"/> class.
         /// </summary>
-        public HttpContextVariationContextAccessor(IHttpContextAccessor httpContextAccessor)
+        public HttpContextVariationContextAccessor(IRequestCache requestCache)
         {
-            HttpContextAccessor = httpContextAccessor;
+            _requestCache = requestCache;
         }
 
         /// <inheritdoc />
         public VariationContext VariationContext
         {
-            get => (VariationContext) HttpContextAccessor.HttpContext?.Items[ContextKey];
-            set => HttpContextAccessor.HttpContext.Items[ContextKey] = value;
+            get => (VariationContext) _requestCache.Get(_contextKey);
+            set => _requestCache.Set(_contextKey, value);
         }
     }
 }
diff --git a/src/Umbraco.Web/Models/PublishedContent/PublishedValueFallback.cs b/src/Umbraco.Abstractions/Models/PublishedContent/PublishedValueFallback.cs
similarity index 94%
rename from src/Umbraco.Web/Models/PublishedContent/PublishedValueFallback.cs
rename to src/Umbraco.Abstractions/Models/PublishedContent/PublishedValueFallback.cs
index 7b467b6d15..6a3cae9120 100644
--- a/src/Umbraco.Web/Models/PublishedContent/PublishedValueFallback.cs
+++ b/src/Umbraco.Abstractions/Models/PublishedContent/PublishedValueFallback.cs
@@ -14,14 +14,16 @@ namespace Umbraco.Web.Models.PublishedContent
     {
         private readonly ILocalizationService _localizationService;
         private readonly IVariationContextAccessor _variationContextAccessor;
+        private readonly IPublishedValueFallback _publishedValueFallback;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="PublishedValueFallback"/> class.
         /// </summary>
-        public PublishedValueFallback(ServiceContext serviceContext, IVariationContextAccessor variationContextAccessor)
+        public PublishedValueFallback(ServiceContext serviceContext, IVariationContextAccessor variationContextAccessor, IPublishedValueFallback publishedValueFallback)
         {
             _localizationService = serviceContext.LocalizationService;
             _variationContextAccessor = variationContextAccessor;
+            _publishedValueFallback = publishedValueFallback;
         }
 
         /// <inheritdoc />
@@ -182,7 +184,7 @@ namespace Umbraco.Web.Models.PublishedContent
             // if we found a content with the property having a value, return that property value
             if (property != null && property.HasValue(culture, segment))
             {
-                value = property.Value<T>(culture, segment);
+                value = property.Value<T>(_publishedValueFallback, culture, segment);
                 return true;
             }
 
@@ -216,7 +218,7 @@ namespace Umbraco.Web.Models.PublishedContent
 
                 if (property.HasValue(culture2, segment))
                 {
-                    value = property.Value<T>(culture2, segment);
+                    value = property.Value<T>(_publishedValueFallback, culture2, segment);
                     return true;
                 }
 
@@ -250,7 +252,7 @@ namespace Umbraco.Web.Models.PublishedContent
 
                 if (content.HasValue(alias, culture2, segment))
                 {
-                    value = content.Value<T>(alias, culture2, segment);
+                    value = content.Value<T>(_publishedValueFallback, alias, culture2, segment);
                     return true;
                 }
 
@@ -287,7 +289,7 @@ namespace Umbraco.Web.Models.PublishedContent
 
                 if (content.HasValue(alias, culture2, segment))
                 {
-                    value = content.Value<T>(alias, culture2, segment);
+                    value = content.Value<T>(_publishedValueFallback, alias, culture2, segment);
                     return true;
                 }
 
diff --git a/src/Umbraco.Infrastructure/Models/PublishedContent/VariationContextAccessorExtensions.cs b/src/Umbraco.Abstractions/Models/PublishedContent/VariationContextAccessorExtensions.cs
similarity index 100%
rename from src/Umbraco.Infrastructure/Models/PublishedContent/VariationContextAccessorExtensions.cs
rename to src/Umbraco.Abstractions/Models/PublishedContent/VariationContextAccessorExtensions.cs
diff --git a/src/Umbraco.Abstractions/Models/Trees/ActionMenuItem.cs b/src/Umbraco.Abstractions/Models/Trees/ActionMenuItem.cs
index 9354417155..fe760fb94d 100644
--- a/src/Umbraco.Abstractions/Models/Trees/ActionMenuItem.cs
+++ b/src/Umbraco.Abstractions/Models/Trees/ActionMenuItem.cs
@@ -1,6 +1,4 @@
-using System;
-using System.Diagnostics.CodeAnalysis;
-using Umbraco.Core;
+using Umbraco.Core;
 using Umbraco.Core.Services;
 
 namespace Umbraco.Web.Models.Trees
diff --git a/src/Umbraco.Web/Models/Trees/CreateChildEntity.cs b/src/Umbraco.Abstractions/Models/Trees/CreateChildEntity.cs
similarity index 100%
rename from src/Umbraco.Web/Models/Trees/CreateChildEntity.cs
rename to src/Umbraco.Abstractions/Models/Trees/CreateChildEntity.cs
diff --git a/src/Umbraco.Web/Models/Trees/ExportMember.cs b/src/Umbraco.Abstractions/Models/Trees/ExportMember.cs
similarity index 100%
rename from src/Umbraco.Web/Models/Trees/ExportMember.cs
rename to src/Umbraco.Abstractions/Models/Trees/ExportMember.cs
diff --git a/src/Umbraco.Infrastructure/Scoping/CallContext.cs b/src/Umbraco.Abstractions/Scoping/CallContext.cs
similarity index 100%
rename from src/Umbraco.Infrastructure/Scoping/CallContext.cs
rename to src/Umbraco.Abstractions/Scoping/CallContext.cs
diff --git a/src/Umbraco.Abstractions/Umbraco.Abstractions.csproj b/src/Umbraco.Abstractions/Umbraco.Abstractions.csproj
index 2eff63c4b8..52322f979a 100644
--- a/src/Umbraco.Abstractions/Umbraco.Abstractions.csproj
+++ b/src/Umbraco.Abstractions/Umbraco.Abstractions.csproj
@@ -24,9 +24,4 @@
             <_Parameter1>Umbraco.Tests.Benchmarks</_Parameter1>
         </AssemblyAttribute>
     </ItemGroup>
-
-    <ItemGroup>
-      <Folder Include="Logging\Viewer" />
-    </ItemGroup>
-    
 </Project>
diff --git a/src/Umbraco.Web/Models/ContentTypeImportModel.cs b/src/Umbraco.Infrastructure/Models/ContentTypeImportModel.cs
similarity index 100%
rename from src/Umbraco.Web/Models/ContentTypeImportModel.cs
rename to src/Umbraco.Infrastructure/Models/ContentTypeImportModel.cs
diff --git a/src/Umbraco.Web/Models/ImageProcessorImageUrlGenerator.cs b/src/Umbraco.Infrastructure/Models/ImageProcessorImageUrlGenerator.cs
similarity index 98%
rename from src/Umbraco.Web/Models/ImageProcessorImageUrlGenerator.cs
rename to src/Umbraco.Infrastructure/Models/ImageProcessorImageUrlGenerator.cs
index e471e9aa4a..f88309d7e3 100644
--- a/src/Umbraco.Web/Models/ImageProcessorImageUrlGenerator.cs
+++ b/src/Umbraco.Infrastructure/Models/ImageProcessorImageUrlGenerator.cs
@@ -5,7 +5,7 @@ using Umbraco.Core.Models;
 
 namespace Umbraco.Web.Models
 {
-    internal class ImageProcessorImageUrlGenerator : IImageUrlGenerator
+    public class ImageProcessorImageUrlGenerator : IImageUrlGenerator
     {
         public string GetImageUrl(ImageUrlGenerationOptions options)
         {
diff --git a/src/Umbraco.Web/Models/LocalPackageInstallModel.cs b/src/Umbraco.Infrastructure/Models/LocalPackageInstallModel.cs
similarity index 100%
rename from src/Umbraco.Web/Models/LocalPackageInstallModel.cs
rename to src/Umbraco.Infrastructure/Models/LocalPackageInstallModel.cs
diff --git a/src/Umbraco.Infrastructure/Runtime/CoreInitialComposer.cs b/src/Umbraco.Infrastructure/Runtime/CoreInitialComposer.cs
index e22041a682..ab95768f4b 100644
--- a/src/Umbraco.Infrastructure/Runtime/CoreInitialComposer.cs
+++ b/src/Umbraco.Infrastructure/Runtime/CoreInitialComposer.cs
@@ -20,6 +20,7 @@ using Umbraco.Core.Serialization;
 using Umbraco.Core.Services;
 using Umbraco.Core.Strings;
 using Umbraco.Core.Sync;
+using Umbraco.Web.Models.PublishedContent;
 using Umbraco.Web.PublishedCache;
 using IntegerValidator = Umbraco.Core.PropertyEditors.Validators.IntegerValidator;
 
@@ -141,6 +142,8 @@ namespace Umbraco.Core.Runtime
 
             // register the published snapshot accessor - the "current" published snapshot is in the umbraco context
             composition.RegisterUnique<IPublishedSnapshotAccessor, UmbracoContextPublishedSnapshotAccessor>();
+
+            composition.RegisterUnique<IVariationContextAccessor, HybridVariationContextAccessor>();
         }
     }
 }
diff --git a/src/Umbraco.Tests/LegacyXmlPublishedCache/XmlPublishedContent.cs b/src/Umbraco.Tests/LegacyXmlPublishedCache/XmlPublishedContent.cs
index 4d6f57f490..b1ee6a7c4d 100644
--- a/src/Umbraco.Tests/LegacyXmlPublishedCache/XmlPublishedContent.cs
+++ b/src/Umbraco.Tests/LegacyXmlPublishedCache/XmlPublishedContent.cs
@@ -439,11 +439,6 @@ namespace Umbraco.Tests.LegacyXmlPublishedCache
             return (IPublishedContent) appCache.Get(key, () => (new XmlPublishedContent(node, isPreviewing, appCache, contentTypeCache, variationContextAccessor)).CreateModel(Current.PublishedModelFactory));
         }
 
-        public static void ClearRequest()
-        {
-            Current.AppCaches.RequestCache.ClearByKey(CacheKeyPrefix);
-        }
-
         private const string CacheKeyPrefix = "CONTENTCACHE_XMLPUBLISHEDCONTENT_";
     }
 }
diff --git a/src/Umbraco.Tests/Routing/UmbracoModuleTests.cs b/src/Umbraco.Tests/Routing/UmbracoModuleTests.cs
index d4c242a762..c601c48148 100644
--- a/src/Umbraco.Tests/Routing/UmbracoModuleTests.cs
+++ b/src/Umbraco.Tests/Routing/UmbracoModuleTests.cs
@@ -42,7 +42,8 @@ namespace Umbraco.Tests.Routing
                 logger,
                 null, // FIXME: PublishedRouter complexities...
                 Mock.Of<IUmbracoContextFactory>(),
-                new RoutableDocumentFilter(globalSettings, IOHelper)
+                new RoutableDocumentFilter(globalSettings, IOHelper),
+                AppCaches.RequestCache
             );
 
             runtime.Level = RuntimeLevel.Run;
diff --git a/src/Umbraco.Tests/Security/BackOfficeCookieManagerTests.cs b/src/Umbraco.Tests/Security/BackOfficeCookieManagerTests.cs
index 7ff0776ba8..b16c739553 100644
--- a/src/Umbraco.Tests/Security/BackOfficeCookieManagerTests.cs
+++ b/src/Umbraco.Tests/Security/BackOfficeCookieManagerTests.cs
@@ -8,7 +8,6 @@ using Moq;
 using NUnit.Framework;
 using Umbraco.Core;
 using Umbraco.Web.Composing;
-using Umbraco.Tests.TestHelpers;
 using Umbraco.Tests.Testing;
 using Umbraco.Tests.Testing.Objects.Accessors;
 using Umbraco.Web;
@@ -39,7 +38,7 @@ namespace Umbraco.Tests.Security
 
             var runtime = Mock.Of<IRuntimeState>(x => x.Level == RuntimeLevel.Install);
             var mgr = new BackOfficeCookieManager(
-                Mock.Of<IUmbracoContextAccessor>(accessor => accessor.UmbracoContext == umbracoContext), runtime, TestObjects.GetGlobalSettings(), TestHelper.IOHelper);
+                Mock.Of<IUmbracoContextAccessor>(accessor => accessor.UmbracoContext == umbracoContext), runtime, TestObjects.GetGlobalSettings(), IOHelper, AppCaches.RequestCache);
 
             var result = mgr.ShouldAuthenticateRequest(Mock.Of<IOwinContext>(), new Uri("http://localhost/umbraco"));
 
@@ -58,7 +57,7 @@ namespace Umbraco.Tests.Security
                 new TestVariationContextAccessor(), IOHelper);
 
             var runtime = Mock.Of<IRuntimeState>(x => x.Level == RuntimeLevel.Run);
-            var mgr = new BackOfficeCookieManager(Mock.Of<IUmbracoContextAccessor>(accessor => accessor.UmbracoContext == umbCtx), runtime,  TestObjects.GetGlobalSettings(), TestHelper.IOHelper);
+            var mgr = new BackOfficeCookieManager(Mock.Of<IUmbracoContextAccessor>(accessor => accessor.UmbracoContext == umbCtx), runtime,  TestObjects.GetGlobalSettings(), IOHelper, AppCaches.RequestCache);
 
             var request = new Mock<OwinRequest>();
             request.Setup(owinRequest => owinRequest.Uri).Returns(new Uri("http://localhost/umbraco"));
diff --git a/src/Umbraco.Tests/TestHelpers/BaseWebTest.cs b/src/Umbraco.Tests/TestHelpers/BaseWebTest.cs
index ee922cdfcb..6f07b1ecd2 100644
--- a/src/Umbraco.Tests/TestHelpers/BaseWebTest.cs
+++ b/src/Umbraco.Tests/TestHelpers/BaseWebTest.cs
@@ -29,6 +29,7 @@ namespace Umbraco.Tests.TestHelpers
         protected override void Compose()
         {
             base.Compose();
+            base.Compose();
 
             Composition.RegisterUnique<IPublishedValueFallback, PublishedValueFallback>();
             Composition.RegisterUnique<IProfilingLogger, ProfilingLogger>();
diff --git a/src/Umbraco.Tests/Views/web.config b/src/Umbraco.Tests/Views/web.config
new file mode 100644
index 0000000000..efd80424e5
--- /dev/null
+++ b/src/Umbraco.Tests/Views/web.config
@@ -0,0 +1,74 @@
+<?xml version="1.0"?>
+
+<configuration>
+    <configSections>
+        <sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
+            <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
+            <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
+        </sectionGroup>
+    </configSections>
+
+    <system.web.webPages.razor>
+        <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
+        <pages pageBaseType="System.Web.Mvc.WebViewPage">
+            <namespaces>
+                <add namespace="System.Web.Mvc" />
+                <add namespace="System.Web.Mvc.Ajax" />
+                <add namespace="System.Web.Mvc.Html" />
+                <add namespace="System.Web.Routing" />
+                <add namespace="Umbraco.Web" />
+                <add namespace="Umbraco.Core" />
+                <add namespace="Umbraco.Core.Models" />
+                <add namespace="Umbraco.Core.Models.PublishedContent" />
+                <add namespace="Umbraco.Web.Mvc" />
+                <add namespace="Examine" />
+                <add namespace="Umbraco.Web.PublishedModels" />
+            </namespaces>
+        </pages>
+    </system.web.webPages.razor>
+
+    <appSettings>
+        <add key="webpages:Enabled" value="false" />
+    </appSettings>
+
+    <system.webServer>
+        <handlers>
+            <remove name="BlockViewHandler"/>
+            <add name="BlockViewHandler" path="*" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" />
+        </handlers>
+    </system.webServer>
+
+    <system.web>
+        <compilation targetFramework="4.7.2">
+            <assemblies>
+                <add assembly="System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
+
+                <!--
+                    Views are compiled by the Microsoft.CodeDom.Providers.DotNetCompilerPlatform which uses the Roslyn compiler
+                    from ~/bin/roslyn to expose an ICodeProvider implementation to System.CodeDom.
+
+                    For instance, starting with package 1.4.0 (which contains version 1.2.2.0) System.Collections.Immutable
+                    lists netstandard2.0 as a supported target, whereas package 1.3.1 only listed net45. So now, when
+                    installing, NuGet picks the netstandard2.0 version, thus introducing a dependency to netstandard2.0.
+                    
+                    Somehow, transitive dependencies are not working correctly, and either (a) NuGet fails to properly
+                    register this dependency, or (b) when reference assemblies are gathered before compiling views, this
+                    dependency is missed. In any case, the result is that the ICodeProvider is passed a list of referenced
+                    assemblies that is missing .NET Standard.
+
+                    It may be a mix of both. NuGet registers the dependency well enough, that we can actually build the
+                    whole application - but it is not doing something that is required in order to have .NET Standard
+                    being a dependency when building views.
+
+                    See also: https://stackoverflow.com/questions/50165910
+
+                    Funny enough, the CSharpCompiler already explicitly adds System.Runtime as a referenced assembly,
+                    with a comment mentioning an issue. But it's not adding .NET Standard. So, for the time being, to be sure,
+                    we are adding both here.
+                -->
+                <add assembly="System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
+                <add assembly="netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51" />                
+            </assemblies>
+        </compilation>
+    </system.web>
+</configuration>
diff --git a/src/Umbraco.Web.UI/Umbraco/Views/AuthorizeUpgrade.cshtml b/src/Umbraco.Web.UI/Umbraco/Views/AuthorizeUpgrade.cshtml
index e95057efe9..11033aa785 100644
--- a/src/Umbraco.Web.UI/Umbraco/Views/AuthorizeUpgrade.cshtml
+++ b/src/Umbraco.Web.UI/Umbraco/Views/AuthorizeUpgrade.cshtml
@@ -48,7 +48,7 @@
             redirectUrl = Url.Action("AuthorizeUpgrade", "BackOffice")
         });
     }
-    @Html.BareMinimumServerVariablesScript(Url, externalLoginUrl, Model.Features, Model.GlobalSettings, Model.UmbracoVersion, Model.UmbracoSettingsSection, Model.IOHelper, Model.TreeCollection)
+    @Html.BareMinimumServerVariablesScript(Url, externalLoginUrl, Model.Features, Model.GlobalSettings, Model.UmbracoVersion, Model.UmbracoSettingsSection, Model.IOHelper, Model.TreeCollection, Model.HttpContextAccessor, Model.HostingEnvironment)
 
     <script type="text/javascript">
     document.angularReady = function (app) {
diff --git a/src/Umbraco.Web.UI/Umbraco/Views/Default.cshtml b/src/Umbraco.Web.UI/Umbraco/Views/Default.cshtml
index e51adb322f..1bdb7fae1b 100644
--- a/src/Umbraco.Web.UI/Umbraco/Views/Default.cshtml
+++ b/src/Umbraco.Web.UI/Umbraco/Views/Default.cshtml
@@ -110,7 +110,7 @@
         on-login="hideLoginScreen()">
     </umb-login>
 
-    @Html.BareMinimumServerVariablesScript(Url, Url.Action("ExternalLogin", "BackOffice", new { area = ViewData.GetUmbracoPath() }), Model.Features, Model.GlobalSettings, Model.UmbracoVersion, Model.UmbracoSettingsSection, Model.IOHelper, Model.TreeCollection)
+    @Html.BareMinimumServerVariablesScript(Url, Url.Action("ExternalLogin", "BackOffice", new { area = ViewData.GetUmbracoPath() }), Model.Features, Model.GlobalSettings, Model.UmbracoVersion, Model.UmbracoSettingsSection, Model.IOHelper, Model.TreeCollection, Model.HttpContextAccessor, Model.HostingEnvironment)
 
     <script>
 
diff --git a/src/Umbraco.Web/BatchedDatabaseServerMessenger.cs b/src/Umbraco.Web/BatchedDatabaseServerMessenger.cs
index 8a6862b018..a893fa6b49 100644
--- a/src/Umbraco.Web/BatchedDatabaseServerMessenger.cs
+++ b/src/Umbraco.Web/BatchedDatabaseServerMessenger.cs
@@ -28,22 +28,14 @@ namespace Umbraco.Web
     public class BatchedDatabaseServerMessenger : DatabaseServerMessenger
     {
         private readonly IUmbracoDatabaseFactory _databaseFactory;
-        private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly IRequestCache _requestCache;
 
         public BatchedDatabaseServerMessenger(
-            IRuntimeState runtime,
-            IUmbracoDatabaseFactory databaseFactory,
-            IScopeProvider scopeProvider,
-            ISqlContext sqlContext,
-            IProfilingLogger proflog,
-            DatabaseServerMessengerOptions options,
-            IHostingEnvironment hostingEnvironment,
-            CacheRefresherCollection cacheRefreshers,
-            IHttpContextAccessor httpContextAccessor)
+            IRuntimeState runtime, IUmbracoDatabaseFactory databaseFactory, IScopeProvider scopeProvider, ISqlContext sqlContext, IProfilingLogger proflog, DatabaseServerMessengerOptions options, IHostingEnvironment hostingEnvironment, CacheRefresherCollection cacheRefreshers, IRequestCache requestCache)
             : base(runtime, scopeProvider, sqlContext, proflog, true, options, hostingEnvironment, cacheRefreshers)
         {
             _databaseFactory = databaseFactory;
-            _httpContextAccessor = httpContextAccessor;
+            _requestCache = requestCache;
         }
 
         // invoked by DatabaseServerRegistrarAndMessengerComponent
@@ -112,24 +104,18 @@ namespace Umbraco.Web
 
         protected ICollection<RefreshInstructionEnvelope> GetBatch(bool create)
         {
-            // try get the http context from the UmbracoContext, we do this because in the case we are launching an async
-            // thread and we know that the cache refreshers will execute, we will ensure the UmbracoContext and therefore we
-            // can get the http context from it
-            var httpContext = (_httpContextAccessor.HttpContext)
-                // if this is null, it could be that an async thread is calling this method that we weren't aware of and the UmbracoContext
-                // wasn't ensured at the beginning of the thread. We can try to see if the HttpContext.Current is available which might be
-                // the case if the asp.net synchronization context has kicked in
-                ?? (HttpContext.Current == null ? null : new HttpContextWrapper(HttpContext.Current));
-
-            // if no context was found, return null - we cannot not batch
-            if (httpContext == null) return null;
-
             var key = typeof (BatchedDatabaseServerMessenger).Name;
 
+            if (!_requestCache.IsAvailable) return null;
+
             // no thread-safety here because it'll run in only 1 thread (request) at a time
-            var batch = (ICollection<RefreshInstructionEnvelope>)httpContext.Items[key];
+            var batch = (ICollection<RefreshInstructionEnvelope>)_requestCache.Get(key);
             if (batch == null && create)
-                httpContext.Items[key] = batch = new List<RefreshInstructionEnvelope>();
+            {
+                batch = new List<RefreshInstructionEnvelope>();
+                _requestCache.Set(key, batch);
+            }
+
             return batch;
         }
 
diff --git a/src/Umbraco.Web/CacheHelperExtensions.cs b/src/Umbraco.Web/CacheHelperExtensions.cs
index 08d1906980..e27b0db1fc 100644
--- a/src/Umbraco.Web/CacheHelperExtensions.cs
+++ b/src/Umbraco.Web/CacheHelperExtensions.cs
@@ -3,6 +3,7 @@ using System.Web;
 using System.Web.Mvc;
 using System.Web.Mvc.Html;
 using Umbraco.Core.Cache;
+using Umbraco.Core.Hosting;
 
 namespace Umbraco.Web
 {
@@ -16,6 +17,7 @@ namespace Umbraco.Web
         /// Outputs and caches a partial view in MVC
         /// </summary>
         /// <param name="appCaches"></param>
+        /// <param name="hostingEnvironment"></param>
         /// <param name="htmlHelper"></param>
         /// <param name="partialViewName"></param>
         /// <param name="model"></param>
@@ -25,6 +27,7 @@ namespace Umbraco.Web
         /// <returns></returns>
         public static IHtmlString CachedPartialView(
             this AppCaches appCaches,
+            IHostingEnvironment hostingEnvironment,
             HtmlHelper htmlHelper,
             string partialViewName,
             object model,
@@ -33,7 +36,7 @@ namespace Umbraco.Web
             ViewDataDictionary viewData = null)
         {
             //disable cached partials in debug mode: http://issues.umbraco.org/issue/U4-5940
-            if (htmlHelper.ViewContext.HttpContext.IsDebuggingEnabled)
+            if (hostingEnvironment.IsDebugMode)
             {
                 // just return a normal partial view instead
                 return htmlHelper.Partial(partialViewName, model, viewData);
diff --git a/src/Umbraco.Web/Editors/BackOfficeController.cs b/src/Umbraco.Web/Editors/BackOfficeController.cs
index d68f346b50..64cd0d1a0d 100644
--- a/src/Umbraco.Web/Editors/BackOfficeController.cs
+++ b/src/Umbraco.Web/Editors/BackOfficeController.cs
@@ -27,6 +27,7 @@ using Constants = Umbraco.Core.Constants;
 using JArray = Newtonsoft.Json.Linq.JArray;
 using Umbraco.Core.Configuration.Grid;
 using Umbraco.Core.Configuration.UmbracoSettings;
+using Umbraco.Core.Hosting;
 using Umbraco.Core.IO;
 using Umbraco.Web.Trees;
 
@@ -50,6 +51,8 @@ namespace Umbraco.Web.Editors
         private readonly IUmbracoSettingsSection _umbracoSettingsSection;
         private readonly IIOHelper _ioHelper;
         private readonly TreeCollection _treeCollection;
+        private readonly IHostingEnvironment _hostingEnvironment;
+        private readonly IHttpContextAccessor _httpContextAccessor;
 
         public BackOfficeController(
             IManifestParser manifestParser,
@@ -65,7 +68,9 @@ namespace Umbraco.Web.Editors
             IGridConfig gridConfig,
             IUmbracoSettingsSection umbracoSettingsSection,
             IIOHelper ioHelper,
-            TreeCollection treeCollection)
+            TreeCollection treeCollection,
+            IHostingEnvironment hostingEnvironment,
+            IHttpContextAccessor httpContextAccessor)
             : base(globalSettings, umbracoContextAccessor, services, appCaches, profilingLogger, umbracoHelper)
         {
             _manifestParser = manifestParser;
@@ -76,6 +81,8 @@ namespace Umbraco.Web.Editors
             _umbracoSettingsSection = umbracoSettingsSection ?? throw new ArgumentNullException(nameof(umbracoSettingsSection));
             _ioHelper = ioHelper ?? throw new ArgumentNullException(nameof(ioHelper));
             _treeCollection = treeCollection ?? throw new ArgumentNullException(nameof(treeCollection));
+            _hostingEnvironment = hostingEnvironment;
+            _httpContextAccessor = httpContextAccessor;
         }
 
         protected BackOfficeSignInManager SignInManager => _signInManager ?? (_signInManager = OwinContext.GetBackOfficeSignInManager());
@@ -91,8 +98,8 @@ namespace Umbraco.Web.Editors
         public async Task<ActionResult> Default()
         {
             return await RenderDefaultOrProcessExternalLoginAsync(
-                () => View(GlobalSettings.Path.EnsureEndsWith('/') + "Views/Default.cshtml", new BackOfficeModel(_features, GlobalSettings, _umbracoVersion, _umbracoSettingsSection,_ioHelper, _treeCollection)),
-                () => View(GlobalSettings.Path.EnsureEndsWith('/') + "Views/Default.cshtml", new BackOfficeModel(_features, GlobalSettings, _umbracoVersion, _umbracoSettingsSection, _ioHelper, _treeCollection)));
+                () => View(GlobalSettings.Path.EnsureEndsWith('/') + "Views/Default.cshtml", new BackOfficeModel(_features, GlobalSettings, _umbracoVersion, _umbracoSettingsSection,_ioHelper, _treeCollection, _httpContextAccessor, _hostingEnvironment)),
+                () => View(GlobalSettings.Path.EnsureEndsWith('/') + "Views/Default.cshtml", new BackOfficeModel(_features, GlobalSettings, _umbracoVersion, _umbracoSettingsSection, _ioHelper, _treeCollection, _httpContextAccessor, _hostingEnvironment)));
         }
 
         [HttpGet]
@@ -175,7 +182,7 @@ namespace Umbraco.Web.Editors
         {
             return await RenderDefaultOrProcessExternalLoginAsync(
                 //The default view to render when there is no external login info or errors
-                () => View(GlobalSettings.Path.EnsureEndsWith('/') + "Views/AuthorizeUpgrade.cshtml", new BackOfficeModel(_features, GlobalSettings, _umbracoVersion, _umbracoSettingsSection, _ioHelper, _treeCollection)),
+                () => View(GlobalSettings.Path.EnsureEndsWith('/') + "Views/AuthorizeUpgrade.cshtml", new BackOfficeModel(_features, GlobalSettings, _umbracoVersion, _umbracoSettingsSection, _ioHelper, _treeCollection, _httpContextAccessor, _hostingEnvironment)),
                 //The ActionResult to perform if external login is successful
                 () => Redirect("/"));
         }
@@ -255,7 +262,7 @@ namespace Umbraco.Web.Editors
             }
 
             //cache the result if debugging is disabled
-            var result = HttpContext.IsDebuggingEnabled
+            var result = _hostingEnvironment.IsDebugMode
                 ? GetAssetList()
                 : AppCaches.RuntimeCache.GetCacheItem<JArray>(
                     "Umbraco.Web.Editors.BackOfficeController.GetManifestAssetList",
@@ -282,10 +289,10 @@ namespace Umbraco.Web.Editors
         [MinifyJavaScriptResult(Order = 1)]
         public JavaScriptResult ServerVariables()
         {
-            var serverVars = new BackOfficeServerVariables(Url, _runtimeState, _features, GlobalSettings, _umbracoVersion, _umbracoSettingsSection, _ioHelper, _treeCollection);
+            var serverVars = new BackOfficeServerVariables(Url, _runtimeState, _features, GlobalSettings, _umbracoVersion, _umbracoSettingsSection, _ioHelper, _treeCollection, _httpContextAccessor, _hostingEnvironment);
 
             //cache the result if debugging is disabled
-            var result = HttpContext.IsDebuggingEnabled
+            var result = _hostingEnvironment.IsDebugMode
                 ? ServerVariablesParser.Parse(serverVars.GetServerVariables())
                 : AppCaches.RuntimeCache.GetCacheItem<string>(
                     typeof(BackOfficeController) + "ServerVariables",
diff --git a/src/Umbraco.Web/Editors/BackOfficeModel.cs b/src/Umbraco.Web/Editors/BackOfficeModel.cs
index d9ad5ee25e..0aa289062c 100644
--- a/src/Umbraco.Web/Editors/BackOfficeModel.cs
+++ b/src/Umbraco.Web/Editors/BackOfficeModel.cs
@@ -1,5 +1,6 @@
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Configuration.UmbracoSettings;
+using Umbraco.Core.Hosting;
 using Umbraco.Core.IO;
 using Umbraco.Web.Features;
 using Umbraco.Web.Trees;
@@ -9,7 +10,7 @@ namespace Umbraco.Web.Editors
 
     public class BackOfficeModel
     {
-        public BackOfficeModel(UmbracoFeatures features, IGlobalSettings globalSettings, IUmbracoVersion umbracoVersion, IUmbracoSettingsSection umbracoSettingsSection, IIOHelper ioHelper, TreeCollection treeCollection)
+        public BackOfficeModel(UmbracoFeatures features, IGlobalSettings globalSettings, IUmbracoVersion umbracoVersion, IUmbracoSettingsSection umbracoSettingsSection, IIOHelper ioHelper, TreeCollection treeCollection, IHttpContextAccessor httpContextAccessor, IHostingEnvironment hostingEnvironment)
         {
             Features = features;
             GlobalSettings = globalSettings;
@@ -17,6 +18,8 @@ namespace Umbraco.Web.Editors
             UmbracoSettingsSection = umbracoSettingsSection;
             IOHelper = ioHelper;
             TreeCollection = treeCollection;
+            HttpContextAccessor = httpContextAccessor;
+            HostingEnvironment = hostingEnvironment;
         }
 
         public UmbracoFeatures Features { get; }
@@ -25,5 +28,7 @@ namespace Umbraco.Web.Editors
         public IUmbracoSettingsSection UmbracoSettingsSection { get; }
         public IIOHelper IOHelper { get; }
         public TreeCollection TreeCollection { get; }
+        public IHttpContextAccessor HttpContextAccessor { get; }
+        public IHostingEnvironment HostingEnvironment { get; }
     }
 }
diff --git a/src/Umbraco.Web/Editors/BackOfficePreviewModel.cs b/src/Umbraco.Web/Editors/BackOfficePreviewModel.cs
index 17baac7b3b..321b08266e 100644
--- a/src/Umbraco.Web/Editors/BackOfficePreviewModel.cs
+++ b/src/Umbraco.Web/Editors/BackOfficePreviewModel.cs
@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Configuration.UmbracoSettings;
+using Umbraco.Core.Hosting;
 using Umbraco.Core.IO;
 using Umbraco.Core.Models;
 using Umbraco.Web.Features;
@@ -13,8 +14,8 @@ namespace Umbraco.Web.Editors
         private readonly UmbracoFeatures _features;
         public IEnumerable<ILanguage> Languages { get; }
 
-        public BackOfficePreviewModel(UmbracoFeatures features, IGlobalSettings globalSettings, IUmbracoVersion umbracoVersion, IEnumerable<ILanguage> languages, IUmbracoSettingsSection umbracoSettingsSection, IIOHelper ioHelper, TreeCollection treeCollection)
-            : base(features, globalSettings, umbracoVersion, umbracoSettingsSection, ioHelper, treeCollection)
+        public BackOfficePreviewModel(UmbracoFeatures features, IGlobalSettings globalSettings, IUmbracoVersion umbracoVersion, IEnumerable<ILanguage> languages, IUmbracoSettingsSection umbracoSettingsSection, IIOHelper ioHelper, TreeCollection treeCollection, IHttpContextAccessor httpContextAccessor, IHostingEnvironment hostingEnvironment)
+            : base(features, globalSettings, umbracoVersion, umbracoSettingsSection, ioHelper, treeCollection, httpContextAccessor, hostingEnvironment)
         {
             _features = features;
             Languages = languages;
diff --git a/src/Umbraco.Web/Editors/BackOfficeServerVariables.cs b/src/Umbraco.Web/Editors/BackOfficeServerVariables.cs
index 9d2f59821d..4b5992ac23 100644
--- a/src/Umbraco.Web/Editors/BackOfficeServerVariables.cs
+++ b/src/Umbraco.Web/Editors/BackOfficeServerVariables.cs
@@ -21,6 +21,7 @@ using Umbraco.Web.PropertyEditors;
 using Umbraco.Web.Trees;
 using Constants = Umbraco.Core.Constants;
 using Umbraco.Core.Configuration.UmbracoSettings;
+using Umbraco.Core.Hosting;
 using Umbraco.Core.IO;
 
 namespace Umbraco.Web.Editors
@@ -34,25 +35,25 @@ namespace Umbraco.Web.Editors
         private readonly IRuntimeState _runtimeState;
         private readonly UmbracoFeatures _features;
         private readonly IGlobalSettings _globalSettings;
-        private readonly HttpContextBase _httpContext;
-        private readonly IOwinContext _owinContext;
         private readonly IUmbracoVersion _umbracoVersion;
         private readonly IUmbracoSettingsSection _umbracoSettingsSection;
         private readonly IIOHelper _ioHelper;
         private readonly TreeCollection _treeCollection;
+        private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly IHostingEnvironment _hostingEnvironment;
 
-        internal BackOfficeServerVariables(UrlHelper urlHelper, IRuntimeState runtimeState, UmbracoFeatures features, IGlobalSettings globalSettings, IUmbracoVersion umbracoVersion, IUmbracoSettingsSection umbracoSettingsSection, IIOHelper ioHelper, TreeCollection treeCollection)
+        internal BackOfficeServerVariables(UrlHelper urlHelper, IRuntimeState runtimeState, UmbracoFeatures features, IGlobalSettings globalSettings, IUmbracoVersion umbracoVersion, IUmbracoSettingsSection umbracoSettingsSection, IIOHelper ioHelper, TreeCollection treeCollection, IHttpContextAccessor httpContextAccessor, IHostingEnvironment hostingEnvironment)
         {
             _urlHelper = urlHelper;
             _runtimeState = runtimeState;
             _features = features;
             _globalSettings = globalSettings;
-            _httpContext = _urlHelper.RequestContext.HttpContext;
-            _owinContext = _httpContext.GetOwinContext();
             _umbracoVersion = umbracoVersion;
             _umbracoSettingsSection = umbracoSettingsSection ?? throw new ArgumentNullException(nameof(umbracoSettingsSection));
             _ioHelper = ioHelper ?? throw new ArgumentNullException(nameof(ioHelper));
             _treeCollection = treeCollection ?? throw new ArgumentNullException(nameof(treeCollection));
+            _httpContextAccessor = httpContextAccessor;
+            _hostingEnvironment = hostingEnvironment;
         }
 
         /// <summary>
@@ -368,7 +369,7 @@ namespace Umbraco.Web.Editors
                     }
                 },
                 {
-                    "isDebuggingEnabled", _httpContext.IsDebuggingEnabled
+                    "isDebuggingEnabled", _hostingEnvironment.IsDebugMode
                 },
                 {
                     "application", GetApplicationState()
@@ -377,7 +378,7 @@ namespace Umbraco.Web.Editors
                     "externalLogins", new Dictionary<string, object>
                     {
                         {
-                            "providers", _owinContext.Authentication.GetExternalAuthenticationTypes()
+                            "providers", _httpContextAccessor.HttpContext.GetOwinContext().Authentication.GetExternalAuthenticationTypes()
                                 .Where(p => p.Properties.ContainsKey("UmbracoBackOffice"))
                                 .Select(p => new
                                 {
@@ -464,7 +465,7 @@ namespace Umbraco.Web.Editors
             app.Add("cacheBuster", $"{version}.{_runtimeState.Level}.{ClientDependencySettings.Instance.Version}".GenerateHash());
 
             //useful for dealing with virtual paths on the client side when hosted in virtual directories especially
-            app.Add("applicationPath", _httpContext.Request.ApplicationPath.EnsureEndsWith('/'));
+            app.Add("applicationPath", _httpContextAccessor.HttpContext.Request.ApplicationPath.EnsureEndsWith('/'));
 
             //add the server's GMT time offset in minutes
             app.Add("serverTimeOffset", Convert.ToInt32(DateTimeOffset.Now.Offset.TotalMinutes));
diff --git a/src/Umbraco.Web/Editors/PreviewController.cs b/src/Umbraco.Web/Editors/PreviewController.cs
index 1d8336b921..0b7b4e2b43 100644
--- a/src/Umbraco.Web/Editors/PreviewController.cs
+++ b/src/Umbraco.Web/Editors/PreviewController.cs
@@ -6,6 +6,7 @@ using System.Web.UI;
 using Umbraco.Core;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Configuration.UmbracoSettings;
+using Umbraco.Core.Hosting;
 using Umbraco.Core.IO;
 using Umbraco.Core.Services;
 using Umbraco.Web.Composing;
@@ -31,6 +32,8 @@ namespace Umbraco.Web.Editors
         private readonly IUmbracoSettingsSection _umbracoSettingsSection;
         private readonly IIOHelper _ioHelper;
         private readonly TreeCollection _treeCollection;
+        private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly IHostingEnvironment _hostingEnvironment;
 
         public PreviewController(
             UmbracoFeatures features,
@@ -41,7 +44,9 @@ namespace Umbraco.Web.Editors
             IUmbracoVersion umbracoVersion,
             IUmbracoSettingsSection umbracoSettingsSection,
             IIOHelper ioHelper,
-            TreeCollection treeCollection)
+            TreeCollection treeCollection,
+            IHttpContextAccessor httpContextAccessor,
+            IHostingEnvironment hostingEnvironment)
         {
             _features = features;
             _globalSettings = globalSettings;
@@ -52,6 +57,8 @@ namespace Umbraco.Web.Editors
             _umbracoSettingsSection = umbracoSettingsSection ?? throw new ArgumentNullException(nameof(umbracoSettingsSection));
             _ioHelper = ioHelper ?? throw new ArgumentNullException(nameof(ioHelper));
             _treeCollection = treeCollection;
+            _httpContextAccessor = httpContextAccessor;
+            _hostingEnvironment = hostingEnvironment;
         }
 
         [UmbracoAuthorize(redirectToUmbracoLogin: true)]
@@ -60,7 +67,7 @@ namespace Umbraco.Web.Editors
         {
             var availableLanguages = _localizationService.GetAllLanguages();
 
-            var model = new BackOfficePreviewModel(_features, _globalSettings, _umbracoVersion, availableLanguages, _umbracoSettingsSection, _ioHelper, _treeCollection);
+            var model = new BackOfficePreviewModel(_features, _globalSettings, _umbracoVersion, availableLanguages, _umbracoSettingsSection, _ioHelper, _treeCollection, _httpContextAccessor, _hostingEnvironment);
 
             if (model.PreviewExtendedHeaderView.IsNullOrWhiteSpace() == false)
             {
diff --git a/src/Umbraco.Web/HtmlHelperBackOfficeExtensions.cs b/src/Umbraco.Web/HtmlHelperBackOfficeExtensions.cs
index b96ff26a83..1375bc5d98 100644
--- a/src/Umbraco.Web/HtmlHelperBackOfficeExtensions.cs
+++ b/src/Umbraco.Web/HtmlHelperBackOfficeExtensions.cs
@@ -5,6 +5,7 @@ using System.Web;
 using System.Web.Mvc;
 using Microsoft.Owin.Security;
 using Newtonsoft.Json;
+using Umbraco.Core.Hosting;
 using Umbraco.Core.IO;
 using Umbraco.Web.Composing;
 using Umbraco.Web.Editors;
@@ -39,9 +40,9 @@ namespace Umbraco.Web
         /// These are the bare minimal server variables that are required for the application to start without being authenticated,
         /// we will load the rest of the server vars after the user is authenticated.
         /// </remarks>
-        public static IHtmlString BareMinimumServerVariablesScript(this HtmlHelper html, UrlHelper uri, string externalLoginsUrl, UmbracoFeatures features, IGlobalSettings globalSettings, IUmbracoVersion umbracoVersion, IUmbracoSettingsSection umbracoSettingsSection, IIOHelper ioHelper, TreeCollection treeCollection)
+        public static IHtmlString BareMinimumServerVariablesScript(this HtmlHelper html, UrlHelper uri, string externalLoginsUrl, UmbracoFeatures features, IGlobalSettings globalSettings, IUmbracoVersion umbracoVersion, IUmbracoSettingsSection umbracoSettingsSection, IIOHelper ioHelper, TreeCollection treeCollection, IHttpContextAccessor httpContextAccessor, IHostingEnvironment hostingEnvironment)
         {
-            var serverVars = new BackOfficeServerVariables(uri, Current.RuntimeState, features, globalSettings, umbracoVersion, umbracoSettingsSection, ioHelper, treeCollection);
+            var serverVars = new BackOfficeServerVariables(uri, Current.RuntimeState, features, globalSettings, umbracoVersion, umbracoSettingsSection, ioHelper, treeCollection, httpContextAccessor, hostingEnvironment);
             var minVars = serverVars.BareMinimumServerVariables();
 
             var str = @"<script type=""text/javascript"">
diff --git a/src/Umbraco.Web/HtmlHelperRenderExtensions.cs b/src/Umbraco.Web/HtmlHelperRenderExtensions.cs
index 38de699b7d..d361ca0af2 100644
--- a/src/Umbraco.Web/HtmlHelperRenderExtensions.cs
+++ b/src/Umbraco.Web/HtmlHelperRenderExtensions.cs
@@ -105,7 +105,7 @@ namespace Umbraco.Web
                 var contextualKey = contextualKeyBuilder(model, viewData);
                 cacheKey.AppendFormat("c{0}-", contextualKey);
             }
-            return Current.AppCaches.CachedPartialView(htmlHelper, partialViewName, model, cachedSeconds, cacheKey.ToString(), viewData);
+            return Current.AppCaches.CachedPartialView(Current.HostingEnvironment, htmlHelper, partialViewName, model, cachedSeconds, cacheKey.ToString(), viewData);
         }
 
         public static MvcHtmlString EditorFor<T>(this HtmlHelper htmlHelper, string templateName = "", string htmlFieldName = "", object additionalViewData = null)
diff --git a/src/Umbraco.Web/HttpContextExtensions.cs b/src/Umbraco.Web/HttpContextExtensions.cs
index 22eb4d1917..bb080c5618 100644
--- a/src/Umbraco.Web/HttpContextExtensions.cs
+++ b/src/Umbraco.Web/HttpContextExtensions.cs
@@ -4,20 +4,6 @@ namespace Umbraco.Core
 {
     public static class HttpContextExtensions
     {
-        public static T GetContextItem<T>(this HttpContextBase httpContext, string key)
-        {
-            if (httpContext == null) return default(T);
-            if (httpContext.Items[key] == null) return default(T);
-            var val = httpContext.Items[key].TryConvertTo<T>();
-            if (val) return val.Result;
-            return default(T);
-        }
-
-        public static T GetContextItem<T>(this HttpContext httpContext, string key)
-        {
-            return new HttpContextWrapper(httpContext).GetContextItem<T>(key);
-        }
-
         public static string GetCurrentRequestIpAddress(this HttpContextBase httpContext)
         {
             if (httpContext == null)
diff --git a/src/Umbraco.Web/HttpContextUmbracoContextAccessor.cs b/src/Umbraco.Web/HttpContextUmbracoContextAccessor.cs
index a6f89ec154..5a522b02c7 100644
--- a/src/Umbraco.Web/HttpContextUmbracoContextAccessor.cs
+++ b/src/Umbraco.Web/HttpContextUmbracoContextAccessor.cs
@@ -1,31 +1,29 @@
 using System;
+using Umbraco.Core.Cache;
 
 namespace Umbraco.Web
 {
     internal class HttpContextUmbracoContextAccessor : IUmbracoContextAccessor
     {
+        private readonly IRequestCache _requestCache;
         private const string HttpContextItemKey = "Umbraco.Web.UmbracoContext";
-        private readonly IHttpContextAccessor _httpContextAccessor;
 
-        public HttpContextUmbracoContextAccessor(IHttpContextAccessor httpContextAccessor)
+        public HttpContextUmbracoContextAccessor(IRequestCache requestCache)
         {
-            _httpContextAccessor = httpContextAccessor;
+            _requestCache = requestCache;
         }
 
         public IUmbracoContext UmbracoContext
         {
             get
             {
-                var httpContext = _httpContextAccessor.HttpContext;
-                if (httpContext == null) throw new Exception("oops:httpContext");
-                return (IUmbracoContext) httpContext.Items[HttpContextItemKey];
+                if (!_requestCache.IsAvailable) throw new InvalidOperationException("No request cache available");
+                return (IUmbracoContext) _requestCache.Get(HttpContextItemKey);
             }
-
             set
             {
-                var httpContext = _httpContextAccessor.HttpContext;
-                if (httpContext == null) throw new Exception("oops:httpContext");
-                httpContext.Items[HttpContextItemKey] = value;
+                if (!_requestCache.IsAvailable)  throw new InvalidOperationException("No request cache available");
+                _requestCache.Set(HttpContextItemKey, value);
             }
         }
     }
diff --git a/src/Umbraco.Web/HybridUmbracoContextAccessor.cs b/src/Umbraco.Web/HybridUmbracoContextAccessor.cs
index 3c22826f30..bb8e2d6993 100644
--- a/src/Umbraco.Web/HybridUmbracoContextAccessor.cs
+++ b/src/Umbraco.Web/HybridUmbracoContextAccessor.cs
@@ -1,4 +1,6 @@
-namespace Umbraco.Web
+using Umbraco.Core.Cache;
+
+namespace Umbraco.Web
 {
     /// <summary>
     /// Implements a hybrid <see cref="IUmbracoContextAccessor"/>.
@@ -8,8 +10,8 @@
         /// <summary>
         /// Initializes a new instance of the <see cref="HybridUmbracoContextAccessor"/> class.
         /// </summary>
-        public HybridUmbracoContextAccessor(IHttpContextAccessor httpContextAccessor)
-            : base(httpContextAccessor)
+        public HybridUmbracoContextAccessor(IRequestCache requestCache)
+            : base(requestCache)
         { }
 
         /// <inheritdoc />
diff --git a/src/Umbraco.Web/Install/InstallSteps/NewInstallStep.cs b/src/Umbraco.Web/Install/InstallSteps/NewInstallStep.cs
index 9a451ba010..6122e2924a 100644
--- a/src/Umbraco.Web/Install/InstallSteps/NewInstallStep.cs
+++ b/src/Umbraco.Web/Install/InstallSteps/NewInstallStep.cs
@@ -29,26 +29,24 @@ namespace Umbraco.Web.Install.InstallSteps
     [InstallSetupStep(InstallationType.NewInstall, "User", 20, "")]
     internal class NewInstallStep : InstallSetupStep<UserModel>
     {
-        private readonly HttpContextBase _http;
+        private readonly IHttpContextAccessor _httpContextAccessor;
         private readonly IUserService _userService;
         private readonly DatabaseBuilder _databaseBuilder;
         private static HttpClient _httpClient;
         private readonly IGlobalSettings _globalSettings;
         private readonly IUserPasswordConfiguration _passwordConfiguration;
-        private readonly BackOfficeUserManager<BackOfficeIdentityUser> _userManager;
         private readonly IUmbracoSettingsSection _umbracoSettingsSection;
         private readonly IConnectionStrings _connectionStrings;
 
-        public NewInstallStep(HttpContextBase http, IUserService userService, DatabaseBuilder databaseBuilder, IGlobalSettings globalSettings, IUserPasswordConfiguration passwordConfiguration, IUmbracoSettingsSection umbracoSettingsSection, IConnectionStrings connectionStrings)
+        public NewInstallStep(IHttpContextAccessor httpContextAccessor, IUserService userService, DatabaseBuilder databaseBuilder, IGlobalSettings globalSettings, IUserPasswordConfiguration passwordConfiguration, IUmbracoSettingsSection umbracoSettingsSection, IConnectionStrings connectionStrings)
         {
-            _http = http;
-            _userService = userService;
-            _databaseBuilder = databaseBuilder;
-            _globalSettings = globalSettings;
+            _httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException(nameof(httpContextAccessor));
+            _userService = userService ?? throw new ArgumentNullException(nameof(userService));
+            _databaseBuilder = databaseBuilder ?? throw new ArgumentNullException(nameof(databaseBuilder));
+            _globalSettings = globalSettings ?? throw new ArgumentNullException(nameof(globalSettings));
             _passwordConfiguration = passwordConfiguration ?? throw new ArgumentNullException(nameof(passwordConfiguration));
             _umbracoSettingsSection = umbracoSettingsSection ?? throw new ArgumentNullException(nameof(umbracoSettingsSection));
             _connectionStrings = connectionStrings ?? throw new ArgumentNullException(nameof(connectionStrings));
-            _userManager = _http.GetOwinContext().GetBackOfficeUserManager();
         }
 
         public override async Task<InstallSetupResult> ExecuteAsync(UserModel user)
@@ -59,15 +57,16 @@ namespace Umbraco.Web.Install.InstallSteps
                 throw new InvalidOperationException("Could not find the super user!");
             }
 
-            var membershipUser = await _userManager.FindByIdAsync(Constants.Security.SuperUserId);
+            var userManager = _httpContextAccessor.HttpContext.GetOwinContext().GetBackOfficeUserManager();
+            var membershipUser = await userManager.FindByIdAsync(Constants.Security.SuperUserId);
             if (membershipUser == null)
             {
                 throw new InvalidOperationException($"No user found in membership provider with id of {Constants.Security.SuperUserId}.");
             }
 
             //To change the password here we actually need to reset it since we don't have an old one to use to change
-            var resetToken = await _userManager.GeneratePasswordResetTokenAsync(membershipUser.Id);
-            var resetResult = await _userManager.ChangePasswordWithResetAsync(membershipUser.Id, resetToken, user.Password.Trim());
+            var resetToken = await userManager.GeneratePasswordResetTokenAsync(membershipUser.Id);
+            var resetResult = await userManager.ChangePasswordWithResetAsync(membershipUser.Id, resetToken, user.Password.Trim());
             if (!resetResult.Succeeded)
             {
                 throw new InvalidOperationException("Could not reset password: " + string.Join(", ", resetResult.Errors));
@@ -138,7 +137,7 @@ namespace Umbraco.Web.Install.InstallSteps
 
             // In this one case when it's a brand new install and nothing has been configured, make sure the
             // back office cookie is cleared so there's no old cookies lying around causing problems
-            _http.ExpireCookie(_umbracoSettingsSection.Security.AuthCookieName);
+            _httpContextAccessor.HttpContext.ExpireCookie(_umbracoSettingsSection.Security.AuthCookieName);
 
                 return true;
         }
diff --git a/src/Umbraco.Web/Install/InstallSteps/SetUmbracoVersionStep.cs b/src/Umbraco.Web/Install/InstallSteps/SetUmbracoVersionStep.cs
index 63247f5f0b..6b9e2f392e 100644
--- a/src/Umbraco.Web/Install/InstallSteps/SetUmbracoVersionStep.cs
+++ b/src/Umbraco.Web/Install/InstallSteps/SetUmbracoVersionStep.cs
@@ -18,16 +18,16 @@ namespace Umbraco.Web.Install.InstallSteps
         PerformsAppRestart = true)]
     internal class SetUmbracoVersionStep : InstallSetupStep<object>
     {
-        private readonly HttpContextBase _httpContext;
+        private readonly IHttpContextAccessor _httpContextAccessor;
         private readonly InstallHelper _installHelper;
         private readonly IGlobalSettings _globalSettings;
         private readonly IUserService _userService;
         private readonly IUmbracoVersion _umbracoVersion;
         private readonly IIOHelper _ioHelper;
 
-        public SetUmbracoVersionStep(HttpContextBase httpContext, InstallHelper installHelper, IGlobalSettings globalSettings, IUserService userService, IUmbracoVersion umbracoVersion, IIOHelper ioHelper)
+        public SetUmbracoVersionStep(IHttpContextAccessor httpContextAccessor, InstallHelper installHelper, IGlobalSettings globalSettings, IUserService userService, IUmbracoVersion umbracoVersion, IIOHelper ioHelper)
         {
-            _httpContext = httpContext;
+            _httpContextAccessor = httpContextAccessor;
             _installHelper = installHelper;
             _globalSettings = globalSettings;
             _userService = userService;
@@ -37,7 +37,7 @@ namespace Umbraco.Web.Install.InstallSteps
 
         public override Task<InstallSetupResult> ExecuteAsync(object model)
         {
-            var security = new WebSecurity(_httpContext, _userService, _globalSettings, _ioHelper);
+            var security = new WebSecurity(_httpContextAccessor.HttpContext, _userService, _globalSettings, _ioHelper);
 
             if (security.IsAuthenticated() == false && _globalSettings.ConfigurationStatus.IsNullOrWhiteSpace())
             {
diff --git a/src/Umbraco.Web/Models/PublishedContent/HybridVariationContextAccessor.cs b/src/Umbraco.Web/Models/PublishedContent/HybridVariationContextAccessor.cs
index cb002e11b0..897ff17db4 100644
--- a/src/Umbraco.Web/Models/PublishedContent/HybridVariationContextAccessor.cs
+++ b/src/Umbraco.Web/Models/PublishedContent/HybridVariationContextAccessor.cs
@@ -1,4 +1,5 @@
-using Umbraco.Core.Models.PublishedContent;
+using Umbraco.Core.Cache;
+using Umbraco.Core.Models.PublishedContent;
 
 namespace Umbraco.Web.Models.PublishedContent
 {
@@ -7,8 +8,8 @@ namespace Umbraco.Web.Models.PublishedContent
     /// </summary>
     internal class HybridVariationContextAccessor : HybridAccessorBase<VariationContext>, IVariationContextAccessor
     {
-        public HybridVariationContextAccessor(IHttpContextAccessor httpContextAccessor)
-            : base(httpContextAccessor)
+        public HybridVariationContextAccessor(IRequestCache requestCache)
+            : base(requestCache)
         { }
 
         /// <inheritdoc />
@@ -23,4 +24,4 @@ namespace Umbraco.Web.Models.PublishedContent
             set => Value = value;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/Umbraco.Web/Mvc/MinifyJavaScriptResultAttribute.cs b/src/Umbraco.Web/Mvc/MinifyJavaScriptResultAttribute.cs
index 8dee11b844..49eee35598 100644
--- a/src/Umbraco.Web/Mvc/MinifyJavaScriptResultAttribute.cs
+++ b/src/Umbraco.Web/Mvc/MinifyJavaScriptResultAttribute.cs
@@ -2,6 +2,8 @@
 using System.Web.UI;
 using ClientDependency.Core;
 using ClientDependency.Core.CompositeFiles;
+using Umbraco.Composing;
+using Umbraco.Core.Hosting;
 
 namespace Umbraco.Web.Mvc
 {
@@ -13,6 +15,18 @@ namespace Umbraco.Web.Mvc
     /// </remarks>
     public class MinifyJavaScriptResultAttribute : ActionFilterAttribute
     {
+        private readonly IHostingEnvironment _hostingEnvironment;
+
+        public MinifyJavaScriptResultAttribute()
+        {
+            _hostingEnvironment = Current.HostingEnvironment;
+        }
+
+        public MinifyJavaScriptResultAttribute(IHostingEnvironment hostingEnvironment)
+        {
+            _hostingEnvironment = hostingEnvironment;
+        }
+
         /// <summary>
         /// Minify the result if in release mode
         /// </summary>
@@ -24,7 +38,7 @@ namespace Umbraco.Web.Mvc
             if (filterContext.Result == null) return;
             var jsResult = filterContext.Result as JavaScriptResult;
             if (jsResult == null) return;
-            if (filterContext.HttpContext.IsDebuggingEnabled) return;
+            if (_hostingEnvironment.IsDebugMode) return;
 
             //minify the result
             var result = jsResult.Script;
diff --git a/src/Umbraco.Web/Mvc/UmbracoController.cs b/src/Umbraco.Web/Mvc/UmbracoController.cs
index 68605a9086..fd5ce6073e 100644
--- a/src/Umbraco.Web/Mvc/UmbracoController.cs
+++ b/src/Umbraco.Web/Mvc/UmbracoController.cs
@@ -33,7 +33,7 @@ namespace Umbraco.Web.Mvc
         /// <summary>
         /// Gets or sets the Umbraco context accessor.
         /// </summary>
-        public virtual IUmbracoContextAccessor UmbracoContextAccessor { get; set; }
+        public IUmbracoContextAccessor UmbracoContextAccessor { get; set; }
 
         /// <summary>
         /// Gets or sets the services context.
diff --git a/src/Umbraco.Web/Runtime/WebInitialComposer.cs b/src/Umbraco.Web/Runtime/WebInitialComposer.cs
index 1e3b269e1d..cb65fcd30d 100644
--- a/src/Umbraco.Web/Runtime/WebInitialComposer.cs
+++ b/src/Umbraco.Web/Runtime/WebInitialComposer.cs
@@ -72,7 +72,7 @@ namespace Umbraco.Web.Runtime
             composition.Register<IFilePermissionHelper, FilePermissionHelper>(Lifetime.Singleton);
 
             composition.RegisterUnique<IHttpContextAccessor, AspNetHttpContextAccessor>(); // required for hybrid accessors
-            composition.RegisterUnique<ICookieManager, AspNetCookieManager>(); 
+            composition.RegisterUnique<ICookieManager, AspNetCookieManager>();
 
             composition.ComposeWebMappingProfiles();
 
@@ -89,7 +89,7 @@ namespace Umbraco.Web.Runtime
 
             // register accessors for cultures
             composition.RegisterUnique<IDefaultCultureAccessor, DefaultCultureAccessor>();
-            composition.RegisterUnique<IVariationContextAccessor, HybridVariationContextAccessor>();
+
 
             // register the http context and umbraco context accessors
             // we *should* use the HttpContextUmbracoContextAccessor, however there are cases when
diff --git a/src/Umbraco.Web/Security/AppBuilderExtensions.cs b/src/Umbraco.Web/Security/AppBuilderExtensions.cs
index 27c1b4fdc5..041b56f1c8 100644
--- a/src/Umbraco.Web/Security/AppBuilderExtensions.cs
+++ b/src/Umbraco.Web/Security/AppBuilderExtensions.cs
@@ -11,6 +11,7 @@ using Microsoft.Owin.Security.DataHandler;
 using Microsoft.Owin.Security.DataProtection;
 using Owin;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Configuration.UmbracoSettings;
 using Umbraco.Core.IO;
@@ -153,9 +154,10 @@ namespace Umbraco.Web.Security
             IGlobalSettings globalSettings,
             ISecuritySection securitySection,
             IIOHelper ioHelper,
+            IRequestCache requestCache,
             IUmbracoSettingsSection umbracoSettingsSection)
         {
-            return app.UseUmbracoBackOfficeCookieAuthentication(umbracoContextAccessor, runtimeState, userService, globalSettings, securitySection, ioHelper, PipelineStage.Authenticate, umbracoSettingsSection);
+            return app.UseUmbracoBackOfficeCookieAuthentication(umbracoContextAccessor, runtimeState, userService, globalSettings, securitySection, ioHelper, requestCache, PipelineStage.Authenticate, umbracoSettingsSection);
         }
 
         /// <summary>
@@ -179,11 +181,12 @@ namespace Umbraco.Web.Security
             IGlobalSettings globalSettings,
             ISecuritySection securitySection,
             IIOHelper ioHelper,
+            IRequestCache requestCache,
             PipelineStage stage,
             IUmbracoSettingsSection umbracoSettingsSection)
         {
             //Create the default options and provider
-            var authOptions = app.CreateUmbracoCookieAuthOptions(umbracoContextAccessor, globalSettings, runtimeState, securitySection, ioHelper);
+            var authOptions = app.CreateUmbracoCookieAuthOptions(umbracoContextAccessor, globalSettings, runtimeState, securitySection, ioHelper, requestCache);
 
             authOptions.Provider = new BackOfficeCookieAuthenticationProvider(userService, runtimeState, globalSettings, ioHelper, umbracoSettingsSection)
             {
@@ -198,7 +201,7 @@ namespace Umbraco.Web.Security
 
             };
 
-            return app.UseUmbracoBackOfficeCookieAuthentication(umbracoContextAccessor, runtimeState, globalSettings, securitySection, ioHelper, authOptions, stage);
+            return app.UseUmbracoBackOfficeCookieAuthentication(umbracoContextAccessor, runtimeState, globalSettings, securitySection, ioHelper, requestCache, authOptions, stage);
         }
 
         /// <summary>
@@ -215,7 +218,8 @@ namespace Umbraco.Web.Security
         /// Configurable pipeline stage
         /// </param>
         /// <returns></returns>
-        public static IAppBuilder UseUmbracoBackOfficeCookieAuthentication(this IAppBuilder app, IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState, IGlobalSettings globalSettings, ISecuritySection securitySection, IIOHelper ioHelper, CookieAuthenticationOptions cookieOptions, PipelineStage stage)
+        public static IAppBuilder UseUmbracoBackOfficeCookieAuthentication(this IAppBuilder app, IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState, IGlobalSettings globalSettings,
+            ISecuritySection securitySection, IIOHelper ioHelper, IRequestCache requestCache, CookieAuthenticationOptions cookieOptions, PipelineStage stage)
         {
             if (app == null) throw new ArgumentNullException(nameof(app));
             if (runtimeState == null) throw new ArgumentNullException(nameof(runtimeState));
@@ -225,7 +229,7 @@ namespace Umbraco.Web.Security
             if (cookieOptions.Provider is BackOfficeCookieAuthenticationProvider == false)
                 throw new ArgumentException($"cookieOptions.Provider must be of type {typeof(BackOfficeCookieAuthenticationProvider)}.", nameof(cookieOptions));
 
-            app.UseUmbracoBackOfficeCookieAuthenticationInternal(cookieOptions, runtimeState, stage);
+            app.UseUmbracoBackOfficeCookieAuthenticationInternal(cookieOptions, runtimeState, requestCache, stage);
 
             //don't apply if app is not ready
             if (runtimeState.Level != RuntimeLevel.Upgrade && runtimeState.Level != RuntimeLevel.Run) return app;
@@ -233,7 +237,7 @@ namespace Umbraco.Web.Security
             var cookieAuthOptions = app.CreateUmbracoCookieAuthOptions(
                 umbracoContextAccessor, globalSettings, runtimeState, securitySection,
                 //This defines the explicit path read cookies from for this middleware
-                ioHelper, new[] {$"{globalSettings.Path}/backoffice/UmbracoApi/Authentication/GetRemainingTimeoutSeconds"});
+                ioHelper, requestCache, new[] {$"{globalSettings.Path}/backoffice/UmbracoApi/Authentication/GetRemainingTimeoutSeconds"});
             cookieAuthOptions.Provider = cookieOptions.Provider;
 
             //This is a custom middleware, we need to return the user's remaining logged in seconds
@@ -279,7 +283,7 @@ namespace Umbraco.Web.Security
             });
         }
 
-        private static void UseUmbracoBackOfficeCookieAuthenticationInternal(this IAppBuilder app, CookieAuthenticationOptions options, IRuntimeState runtimeState, PipelineStage stage)
+        private static void UseUmbracoBackOfficeCookieAuthenticationInternal(this IAppBuilder app, CookieAuthenticationOptions options, IRuntimeState runtimeState,  IRequestCache requestCache,  PipelineStage stage)
         {
             if (app == null) throw new ArgumentNullException(nameof(app));
             if (runtimeState == null) throw new ArgumentNullException(nameof(runtimeState));
@@ -290,7 +294,7 @@ namespace Umbraco.Web.Security
             if (runtimeState.Level == RuntimeLevel.Upgrade || runtimeState.Level == RuntimeLevel.Run)
             {
                 //Then our custom middlewares
-                app.Use(typeof(ForceRenewalCookieAuthenticationMiddleware), app, options, Current.UmbracoContextAccessor);
+                app.Use(typeof(ForceRenewalCookieAuthenticationMiddleware), app, options, Current.UmbracoContextAccessor, requestCache);
                 app.Use(typeof(FixWindowsAuthMiddlware));
             }
 
@@ -311,9 +315,9 @@ namespace Umbraco.Web.Security
         /// <remarks>
         /// By default this will be configured to execute on PipelineStage.Authenticate
         /// </remarks>
-        public static IAppBuilder UseUmbracoBackOfficeExternalCookieAuthentication(this IAppBuilder app, IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState,IGlobalSettings globalSettings, IIOHelper ioHelper)
+        public static IAppBuilder UseUmbracoBackOfficeExternalCookieAuthentication(this IAppBuilder app, IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState,IGlobalSettings globalSettings, IIOHelper ioHelper, IRequestCache requestCache)
         {
-            return app.UseUmbracoBackOfficeExternalCookieAuthentication(umbracoContextAccessor, runtimeState, globalSettings, ioHelper, PipelineStage.Authenticate);
+            return app.UseUmbracoBackOfficeExternalCookieAuthentication(umbracoContextAccessor, runtimeState, globalSettings, ioHelper, requestCache, PipelineStage.Authenticate);
         }
 
         /// <summary>
@@ -329,7 +333,7 @@ namespace Umbraco.Web.Security
         /// <returns></returns>
         public static IAppBuilder UseUmbracoBackOfficeExternalCookieAuthentication(this IAppBuilder app,
             IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState,
-            IGlobalSettings globalSettings, IIOHelper ioHelper, PipelineStage stage)
+            IGlobalSettings globalSettings, IIOHelper ioHelper, IRequestCache requestCache, PipelineStage stage)
         {
             if (app == null) throw new ArgumentNullException(nameof(app));
             if (runtimeState == null) throw new ArgumentNullException(nameof(runtimeState));
@@ -342,7 +346,7 @@ namespace Umbraco.Web.Security
                 CookieName = Constants.Security.BackOfficeExternalCookieName,
                 ExpireTimeSpan = TimeSpan.FromMinutes(5),
                 //Custom cookie manager so we can filter requests
-                CookieManager = new BackOfficeCookieManager(umbracoContextAccessor, runtimeState, globalSettings, ioHelper),
+                CookieManager = new BackOfficeCookieManager(umbracoContextAccessor, runtimeState, globalSettings, ioHelper, requestCache),
                 CookiePath = "/",
                 CookieSecure = globalSettings.UseHttps ? CookieSecureOption.Always : CookieSecureOption.SameAsRequest,
                 CookieHttpOnly = true,
@@ -369,9 +373,9 @@ namespace Umbraco.Web.Security
         /// <remarks>
         /// By default this will be configured to execute on PipelineStage.PostAuthenticate
         /// </remarks>
-        public static IAppBuilder UseUmbracoPreviewAuthentication(this IAppBuilder app, IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState, IGlobalSettings globalSettings, ISecuritySection securitySettings, IIOHelper ioHelper)
+        public static IAppBuilder UseUmbracoPreviewAuthentication(this IAppBuilder app, IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState, IGlobalSettings globalSettings, ISecuritySection securitySettings, IIOHelper ioHelper, IRequestCache requestCache)
         {
-            return app.UseUmbracoPreviewAuthentication(umbracoContextAccessor, runtimeState, globalSettings, securitySettings, ioHelper, PipelineStage.PostAuthenticate);
+            return app.UseUmbracoPreviewAuthentication(umbracoContextAccessor, runtimeState, globalSettings, securitySettings, ioHelper, requestCache, PipelineStage.PostAuthenticate);
         }
 
         /// <summary>
@@ -389,11 +393,11 @@ namespace Umbraco.Web.Security
         /// This ensures that during a preview request that the back office use is also Authenticated and that the back office Identity
         /// is added as a secondary identity to the current IPrincipal so it can be used to Authorize the previewed document.
         /// </remarks>
-        public static IAppBuilder UseUmbracoPreviewAuthentication(this IAppBuilder app, IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState, IGlobalSettings globalSettings, ISecuritySection securitySettings, IIOHelper ioHelper, PipelineStage stage)
+        public static IAppBuilder UseUmbracoPreviewAuthentication(this IAppBuilder app, IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtimeState, IGlobalSettings globalSettings, ISecuritySection securitySettings, IIOHelper ioHelper, IRequestCache requestCache, PipelineStage stage)
         {
             if (runtimeState.Level != RuntimeLevel.Run) return app;
 
-            var authOptions = app.CreateUmbracoCookieAuthOptions(umbracoContextAccessor, globalSettings, runtimeState, securitySettings, ioHelper);
+            var authOptions = app.CreateUmbracoCookieAuthOptions(umbracoContextAccessor, globalSettings, runtimeState, securitySettings, ioHelper, requestCache);
             app.Use(typeof(PreviewAuthenticationMiddleware),  authOptions, Current.Configs.Global(), ioHelper);
 
             // This middleware must execute at least on PostAuthentication, by default it is on Authorize
@@ -424,7 +428,7 @@ namespace Umbraco.Web.Security
         /// <returns></returns>
         public static UmbracoBackOfficeCookieAuthOptions CreateUmbracoCookieAuthOptions(this IAppBuilder app,
             IUmbracoContextAccessor umbracoContextAccessor,
-            IGlobalSettings globalSettings, IRuntimeState runtimeState, ISecuritySection securitySettings, IIOHelper ioHelper, string[] explicitPaths = null)
+            IGlobalSettings globalSettings, IRuntimeState runtimeState, ISecuritySection securitySettings, IIOHelper ioHelper, IRequestCache requestCache, string[] explicitPaths = null)
         {
             //this is how aspnet wires up the default AuthenticationTicket protector so we'll use the same code
             var ticketDataFormat = new TicketDataFormat(
@@ -439,7 +443,8 @@ namespace Umbraco.Web.Security
                 globalSettings,
                 runtimeState,
                 ticketDataFormat,
-                ioHelper);
+                ioHelper,
+                requestCache);
 
             return authOptions;
         }
diff --git a/src/Umbraco.Web/Security/AuthenticationExtensions.cs b/src/Umbraco.Web/Security/AuthenticationExtensions.cs
index 1b89002188..1fd8e45c55 100644
--- a/src/Umbraco.Web/Security/AuthenticationExtensions.cs
+++ b/src/Umbraco.Web/Security/AuthenticationExtensions.cs
@@ -169,18 +169,6 @@ namespace Umbraco.Web.Security
             return true;
         }
 
-        /// <summary>
-        /// This will force ticket renewal in the OWIN pipeline
-        /// </summary>
-        /// <param name="http"></param>
-        /// <returns></returns>
-        internal static bool RenewUmbracoAuthTicket(this HttpContext http)
-        {
-            if (http == null) throw new ArgumentNullException("http");
-            http.Items[Constants.Security.ForceReAuthFlag] = true;
-            return true;
-        }
-
         /// <summary>
         /// returns the number of seconds the user has until their auth session times out
         /// </summary>
diff --git a/src/Umbraco.Web/Security/BackOfficeCookieManager.cs b/src/Umbraco.Web/Security/BackOfficeCookieManager.cs
index 5d70b9b09c..b7b39ea4bf 100644
--- a/src/Umbraco.Web/Security/BackOfficeCookieManager.cs
+++ b/src/Umbraco.Web/Security/BackOfficeCookieManager.cs
@@ -5,6 +5,7 @@ using System.Web;
 using Microsoft.Owin;
 using Microsoft.Owin.Infrastructure;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.IO;
 using Umbraco.Core.Security;
@@ -24,19 +25,21 @@ namespace Umbraco.Web.Security
         private readonly IRuntimeState _runtime;
         private readonly IGlobalSettings _globalSettings;
         private readonly IIOHelper _ioHelper;
+        private readonly IRequestCache _requestCache;
         private readonly string[] _explicitPaths;
         private readonly string _getRemainingSecondsPath;
 
-        public BackOfficeCookieManager(IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtime, IGlobalSettings globalSettings, IIOHelper ioHelper)
-            : this(umbracoContextAccessor, runtime, globalSettings, ioHelper,null)
+        public BackOfficeCookieManager(IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtime, IGlobalSettings globalSettings, IIOHelper ioHelper, IRequestCache requestCache)
+            : this(umbracoContextAccessor, runtime, globalSettings, ioHelper,requestCache, null)
         { }
 
-        public BackOfficeCookieManager(IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtime, IGlobalSettings globalSettings, IIOHelper ioHelper, IEnumerable<string> explicitPaths)
+        public BackOfficeCookieManager(IUmbracoContextAccessor umbracoContextAccessor, IRuntimeState runtime, IGlobalSettings globalSettings, IIOHelper ioHelper, IRequestCache requestCache, IEnumerable<string> explicitPaths)
         {
             _umbracoContextAccessor = umbracoContextAccessor;
             _runtime = runtime;
             _globalSettings = globalSettings;
             _ioHelper = ioHelper;
+            _requestCache = requestCache;
             _explicitPaths = explicitPaths?.ToArray();
             _getRemainingSecondsPath = $"{globalSettings.Path}/backoffice/UmbracoApi/Authentication/GetRemainingTimeoutSeconds";
         }
@@ -89,8 +92,6 @@ namespace Umbraco.Web.Security
                 return false;
 
             var request = owinContext.Request;
-            var httpContext = owinContext.TryGetHttpContext();
-
             //check the explicit paths
             if (_explicitPaths != null)
             {
@@ -102,7 +103,7 @@ namespace Umbraco.Web.Security
 
             if (//check the explicit flag
                 (checkForceAuthTokens && owinContext.Get<bool?>(Constants.Security.ForceReAuthFlag) != null)
-                || (checkForceAuthTokens && httpContext.Success && httpContext.Result.Items[Constants.Security.ForceReAuthFlag] != null)
+                || (checkForceAuthTokens && _requestCache.IsAvailable && _requestCache.Get(Constants.Security.ForceReAuthFlag) != null)
                 //check back office
                 || request.Uri.IsBackOfficeRequest(HttpRuntime.AppDomainAppVirtualPath, _globalSettings, _ioHelper)
                 //check installer
diff --git a/src/Umbraco.Web/Security/ForceRenewalCookieAuthenticationHandler.cs b/src/Umbraco.Web/Security/ForceRenewalCookieAuthenticationHandler.cs
index 896a0ca63e..b3092b90c9 100644
--- a/src/Umbraco.Web/Security/ForceRenewalCookieAuthenticationHandler.cs
+++ b/src/Umbraco.Web/Security/ForceRenewalCookieAuthenticationHandler.cs
@@ -3,6 +3,7 @@ using Microsoft.Owin.Security;
 using Microsoft.Owin.Security.Cookies;
 using Microsoft.Owin.Security.Infrastructure;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
 using Umbraco.Core.Security;
 
 namespace Umbraco.Web.Security
@@ -13,10 +14,12 @@ namespace Umbraco.Web.Security
     internal class ForceRenewalCookieAuthenticationHandler : AuthenticationHandler<CookieAuthenticationOptions>
     {
         private readonly IUmbracoContextAccessor _umbracoContextAccessor;
+        private readonly IRequestCache _requestCache;
 
-        public ForceRenewalCookieAuthenticationHandler(IUmbracoContextAccessor umbracoContextAccessor)
+        public ForceRenewalCookieAuthenticationHandler(IUmbracoContextAccessor umbracoContextAccessor, IRequestCache requestCache)
         {
             _umbracoContextAccessor = umbracoContextAccessor;
+            _requestCache = requestCache;
         }
 
         /// <summary>
@@ -68,9 +71,8 @@ namespace Umbraco.Web.Security
             //This is auth'd normally, so OWIN will naturally take care of the cookie renewal
             if (normalAuthUrl) return Task.FromResult(0);
 
-            var httpCtx = Context.TryGetHttpContext();
             //check for the special flag in either the owin or http context
-            var shouldRenew = Context.Get<bool?>(Constants.Security.ForceReAuthFlag) != null || (httpCtx.Success && httpCtx.Result.Items[Constants.Security.ForceReAuthFlag] != null);
+            var shouldRenew = Context.Get<bool?>(Constants.Security.ForceReAuthFlag) != null || (_requestCache.IsAvailable && _requestCache.Get(Constants.Security.ForceReAuthFlag) != null);
 
             if (shouldRenew)
             {
diff --git a/src/Umbraco.Web/Security/ForceRenewalCookieAuthenticationMiddleware.cs b/src/Umbraco.Web/Security/ForceRenewalCookieAuthenticationMiddleware.cs
index 1b72412f1c..b8f8127544 100644
--- a/src/Umbraco.Web/Security/ForceRenewalCookieAuthenticationMiddleware.cs
+++ b/src/Umbraco.Web/Security/ForceRenewalCookieAuthenticationMiddleware.cs
@@ -2,6 +2,7 @@
 using Microsoft.Owin.Security.Cookies;
 using Microsoft.Owin.Security.Infrastructure;
 using Owin;
+using Umbraco.Core.Cache;
 
 namespace Umbraco.Web.Security
 {
@@ -11,19 +12,22 @@ namespace Umbraco.Web.Security
     internal class ForceRenewalCookieAuthenticationMiddleware : CookieAuthenticationMiddleware
     {
         private readonly IUmbracoContextAccessor _umbracoContextAccessor;
+        private readonly IRequestCache _requestCache;
 
         public ForceRenewalCookieAuthenticationMiddleware(
             OwinMiddleware next,
             IAppBuilder app,
             UmbracoBackOfficeCookieAuthOptions options,
-            IUmbracoContextAccessor umbracoContextAccessor) : base(next, app, options)
+            IUmbracoContextAccessor umbracoContextAccessor,
+            IRequestCache requestCache) : base(next, app, options)
         {
             _umbracoContextAccessor = umbracoContextAccessor;
+            _requestCache = requestCache;
         }
 
         protected override AuthenticationHandler<CookieAuthenticationOptions> CreateHandler()
         {
-            return new ForceRenewalCookieAuthenticationHandler(_umbracoContextAccessor);
+            return new ForceRenewalCookieAuthenticationHandler(_umbracoContextAccessor, _requestCache);
         }
     }
 }
diff --git a/src/Umbraco.Web/Security/UmbracoBackOfficeCookieAuthOptions.cs b/src/Umbraco.Web/Security/UmbracoBackOfficeCookieAuthOptions.cs
index 1ad2535c2f..d8c4ca791d 100644
--- a/src/Umbraco.Web/Security/UmbracoBackOfficeCookieAuthOptions.cs
+++ b/src/Umbraco.Web/Security/UmbracoBackOfficeCookieAuthOptions.cs
@@ -3,6 +3,7 @@ using Microsoft.Owin;
 using Microsoft.Owin.Security;
 using Microsoft.Owin.Security.Cookies;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Configuration.UmbracoSettings;
 using Umbraco.Core.IO;
@@ -23,7 +24,8 @@ namespace Umbraco.Web.Security
             IGlobalSettings globalSettings,
             IRuntimeState runtimeState,
             ISecureDataFormat<AuthenticationTicket> secureDataFormat,
-            IIOHelper ioHelper)
+            IIOHelper ioHelper,
+            IRequestCache requestCache)
         {
             var secureDataFormat1 = secureDataFormat ?? throw new ArgumentNullException(nameof(secureDataFormat));
             LoginTimeoutMinutes = globalSettings.TimeOutInMinutes;
@@ -40,7 +42,7 @@ namespace Umbraco.Web.Security
             TicketDataFormat = new UmbracoSecureDataFormat(LoginTimeoutMinutes, secureDataFormat1);
 
             //Custom cookie manager so we can filter requests
-            CookieManager = new BackOfficeCookieManager(umbracoContextAccessor, runtimeState, globalSettings, ioHelper, explicitPaths);
+            CookieManager = new BackOfficeCookieManager(umbracoContextAccessor, runtimeState, globalSettings, ioHelper, requestCache, explicitPaths);
         }
 
         /// <summary>
diff --git a/src/Umbraco.Web/Umbraco.Web.csproj b/src/Umbraco.Web/Umbraco.Web.csproj
index a129e1f4c1..a26d4a565a 100755
--- a/src/Umbraco.Web/Umbraco.Web.csproj
+++ b/src/Umbraco.Web/Umbraco.Web.csproj
@@ -173,7 +173,6 @@
     <Compile Include="Models\Identity\IdentityMapDefinition.cs" />
     <Compile Include="Models\Identity\IdentityUser.cs" />
     <Compile Include="Models\Identity\UserLoginInfoWrapper.cs" />
-    <Compile Include="Models\ImageProcessorImageUrlGenerator.cs" />
     <Compile Include="Models\Mapping\CommonMapper.cs" />
     <Compile Include="Models\Mapping\ContentMapDefinition.cs" />
     <Compile Include="Models\Mapping\ContentPropertyBasicMapper.cs" />
@@ -190,9 +189,11 @@
     <Compile Include="Models\Mapping\TabsAndPropertiesMapper.cs" />
     <Compile Include="Models\Mapping\UserMapDefinition.cs" />
     <Compile Include="Models\Membership\UmbracoMembershipMember.cs" />
-    <Compile Include="Models\PublishedContent\HybridVariationContextAccessor.cs" />
     <Compile Include="Models\Trees\MenuItemCollection.cs" />
     <Compile Include="Models\Trees\MenuItemList.cs" />
+    <Compile Include="Models\Trees\TreeNodeCollection.cs" />
+    <Compile Include="Models\Trees\TreeNodeExtensions.cs" />
+    <Compile Include="Models\Trees\TreeRootNode.cs" />
     <Compile Include="Mvc\HttpUmbracoFormRouteStringException.cs" />
     <Compile Include="Mvc\ModelBindingExceptionFilter.cs" />
     <Compile Include="Mvc\StatusCodeFilterAttribute.cs" />
@@ -308,10 +309,8 @@
     <Compile Include="Features\DisabledFeatures.cs" />
     <Compile Include="Features\EnabledFeatures.cs" />
     <Compile Include="Features\UmbracoFeatures.cs" />
-    <Compile Include="HybridAccessorBase.cs" />
     <Compile Include="HybridUmbracoContextAccessor.cs" />
     <Compile Include="HttpContextUmbracoContextAccessor.cs" />
-    <Compile Include="HybridEventMessagesAccessor.cs" />
     <Compile Include="IHttpContextAccessor.cs" />
     <Compile Include="Composing\CompositionExtensions\WebMappingProfiles.cs" />
     <Compile Include="Editors\BackOfficeNotificationsController.cs" />
@@ -329,10 +328,6 @@
     <Compile Include="Editors\IEditorValidator.cs" />
     <Compile Include="Editors\EditorModelEventManager.cs" />
     <Compile Include="HtmlHelperBackOfficeExtensions.cs" />
-    <Compile Include="Models\ContentTypeImportModel.cs" />
-    <Compile Include="Models\PublishedContent\HttpContextVariationContextAccessor.cs" />
-    <Compile Include="Models\PublishedContent\PublishedValueFallback.cs" />
-    <Compile Include="Models\Trees\ExportMember.cs" />
     <Compile Include="Composing\ModuleInjector.cs" />
     <Compile Include="Mvc\FilteredControllerFactoryCollection.cs" />
     <Compile Include="Mvc\FilteredControllerFactoryCollectionBuilder.cs" />
@@ -381,7 +376,6 @@
     <Compile Include="Editors\PublishedSnapshotCacheStatusController.cs" />
     <Compile Include="Trees\TreeAttribute.cs" />
     <Compile Include="Routing\NotFoundHandlerHelper.cs" />
-    <Compile Include="Models\LocalPackageInstallModel.cs" />
     <Compile Include="Mvc\ControllerContextExtensions.cs" />
     <Compile Include="Mvc\DisableBrowserCacheAttribute.cs" />
     <Compile Include="Mvc\EnsurePartialViewMacroViewContextFilterAttribute.cs" />
@@ -496,7 +490,6 @@
     <Compile Include="Trees\LanguageTreeController.cs" />
     <Compile Include="Trees\MemberTreeController.cs" />
     <Compile Include="Trees\MenuRenderingEventArgs.cs" />
-    <Compile Include="Models\Trees\CreateChildEntity.cs" />
     <Compile Include="Trees\TemplatesTreeController.cs" />
     <Compile Include="Trees\TreeControllerBase.cs" />
     <Compile Include="JavaScript\AssetInitialization.cs" />
@@ -538,10 +531,7 @@
     <Compile Include="FormDataCollectionExtensions.cs" />
     <Compile Include="Trees\MediaTreeController.cs" />
     <Compile Include="Trees\ContentTreeControllerBase.cs" />
-    <Compile Include="Models\Trees\TreeRootNode.cs" />
     <Compile Include="Trees\TreeController.cs" />
-    <Compile Include="Models\Trees\TreeNodeCollection.cs" />
-    <Compile Include="Models\Trees\TreeNodeExtensions.cs" />
     <Compile Include="Trees\TreeNodeRenderingEventArgs.cs" />
     <Compile Include="Trees\TreeNodesRenderingEventArgs.cs" />
     <Compile Include="Trees\TreeQueryStringParameters.cs" />
diff --git a/src/Umbraco.Web/UmbracoDefaultOwinStartup.cs b/src/Umbraco.Web/UmbracoDefaultOwinStartup.cs
index 6b6bdeb0aa..a30f77b217 100644
--- a/src/Umbraco.Web/UmbracoDefaultOwinStartup.cs
+++ b/src/Umbraco.Web/UmbracoDefaultOwinStartup.cs
@@ -2,6 +2,7 @@
 using Microsoft.Owin;
 using Owin;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Configuration.UmbracoSettings;
 using Umbraco.Core.IO;
@@ -34,6 +35,7 @@ namespace Umbraco.Web
         protected UmbracoMapper Mapper => Current.Mapper;
         protected IIpResolver IpResolver => Current.IpResolver;
         protected IIOHelper IOHelper => Current.IOHelper;
+        protected IRequestCache RequestCache => Current.AppCaches.RequestCache;
 
         /// <summary>
         /// Main startup method
@@ -102,9 +104,9 @@ namespace Umbraco.Web
             // Ensure owin is configured for Umbraco back office authentication.
             // Front-end OWIN cookie configuration must be declared after this code.
             app
-                .UseUmbracoBackOfficeCookieAuthentication(UmbracoContextAccessor, RuntimeState, Services.UserService, GlobalSettings, UmbracoSettings.Security, IOHelper, PipelineStage.Authenticate, UmbracoSettings)
-                .UseUmbracoBackOfficeExternalCookieAuthentication(UmbracoContextAccessor, RuntimeState, GlobalSettings, IOHelper, PipelineStage.Authenticate)
-                .UseUmbracoPreviewAuthentication(UmbracoContextAccessor, RuntimeState, GlobalSettings, UmbracoSettings.Security, IOHelper, PipelineStage.Authorize);
+                .UseUmbracoBackOfficeCookieAuthentication(UmbracoContextAccessor, RuntimeState, Services.UserService, GlobalSettings, UmbracoSettings.Security, IOHelper, RequestCache, PipelineStage.Authenticate, UmbracoSettings)
+                .UseUmbracoBackOfficeExternalCookieAuthentication(UmbracoContextAccessor, RuntimeState, GlobalSettings, IOHelper, RequestCache, PipelineStage.Authenticate)
+                .UseUmbracoPreviewAuthentication(UmbracoContextAccessor, RuntimeState, GlobalSettings, UmbracoSettings.Security, IOHelper, RequestCache, PipelineStage.Authorize);
         }
 
         public static event EventHandler<OwinMiddlewareConfiguredEventArgs> MiddlewareConfigured;
diff --git a/src/Umbraco.Web/UmbracoInjectedModule.cs b/src/Umbraco.Web/UmbracoInjectedModule.cs
index 72579188ed..b8fb6d7449 100644
--- a/src/Umbraco.Web/UmbracoInjectedModule.cs
+++ b/src/Umbraco.Web/UmbracoInjectedModule.cs
@@ -4,6 +4,7 @@ using System.Collections.Generic;
 using System.Web;
 using System.Web.Routing;
 using Umbraco.Core;
+using Umbraco.Core.Cache;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.IO;
 using Umbraco.Core.Logging;
@@ -38,6 +39,7 @@ namespace Umbraco.Web
         private readonly IPublishedRouter _publishedRouter;
         private readonly IUmbracoContextFactory _umbracoContextFactory;
         private readonly RoutableDocumentFilter _routableDocumentLookup;
+        private readonly IRequestCache _requestCache;
 
         public UmbracoInjectedModule(
             IGlobalSettings globalSettings,
@@ -45,7 +47,8 @@ namespace Umbraco.Web
             ILogger logger,
             IPublishedRouter publishedRouter,
             IUmbracoContextFactory umbracoContextFactory,
-            RoutableDocumentFilter routableDocumentLookup)
+            RoutableDocumentFilter routableDocumentLookup,
+            IRequestCache requestCache)
         {
             _globalSettings = globalSettings;
             _runtime = runtime;
@@ -53,6 +56,7 @@ namespace Umbraco.Web
             _publishedRouter = publishedRouter;
             _umbracoContextFactory = umbracoContextFactory;
             _routableDocumentLookup = routableDocumentLookup;
+            _requestCache = requestCache;
         }
 
         #region HttpModule event handlers
@@ -305,15 +309,15 @@ namespace Umbraco.Web
         /// Any object that is in the HttpContext.Items collection that is IDisposable will get disposed on the end of the request
         /// </summary>
         /// <param name="http"></param>
-        private void DisposeHttpContextItems(HttpContext http)
+        private void DisposeRequestCacheItems(HttpContext http, IRequestCache requestCache)
         {
             // do not process if client-side request
             if (http.Request.Url.IsClientSideRequest())
                 return;
 
             //get a list of keys to dispose
-            var keys = new HashSet<object>();
-            foreach (DictionaryEntry i in http.Items)
+            var keys = new HashSet<string>();
+            foreach (var i in requestCache)
             {
                 if (i.Value is IDisposeOnRequestEnd || i.Key is IDisposeOnRequestEnd)
                 {
@@ -325,7 +329,7 @@ namespace Umbraco.Web
             {
                 try
                 {
-                    http.Items[k].DisposeIfDisposable();
+                    requestCache.Get(k).DisposeIfDisposable();
                 }
                 catch (Exception ex)
                 {
@@ -376,7 +380,7 @@ namespace Umbraco.Web
             {
                 var httpContext = ((HttpApplication) sender).Context;
 
-                LogHttpRequest.TryGetCurrentHttpRequestId(out var httpRequestId, Current.AppCaches.RequestCache);
+                LogHttpRequest.TryGetCurrentHttpRequestId(out var httpRequestId, _requestCache);
 
                 _logger.Verbose<UmbracoModule>("Begin request [{HttpRequestId}]: {RequestUrl}", httpRequestId, httpContext.Request.Url);
                 BeginRequest(new HttpContextWrapper(httpContext));
@@ -421,14 +425,14 @@ namespace Umbraco.Web
 
                 if (Current.UmbracoContext != null && Current.UmbracoContext.IsFrontEndUmbracoRequest)
                 {
-                    LogHttpRequest.TryGetCurrentHttpRequestId(out var httpRequestId, Current.AppCaches.RequestCache);
+                    LogHttpRequest.TryGetCurrentHttpRequestId(out var httpRequestId, _requestCache);
 
                     _logger.Verbose<UmbracoModule>("End Request [{HttpRequestId}]: {RequestUrl} ({RequestDuration}ms)", httpRequestId, httpContext.Request.Url, DateTime.Now.Subtract(Current.UmbracoContext.ObjectCreated).TotalMilliseconds);
                 }
 
                 UmbracoModule.OnEndRequest(this, new UmbracoRequestEventArgs(Current.UmbracoContext, new HttpContextWrapper(httpContext)));
 
-                DisposeHttpContextItems(httpContext);
+                DisposeRequestCacheItems(httpContext, _requestCache);
             };
         }