resolves remaining PR comments

src/Umbraco.Web.BackOffice/AspNetCore/AspNetCoreSessionIdResolver.cs

@@ -18,10 +18,11 @@ namespace Umbraco.Web.BackOffice.AspNetCore
         {
             get
             {
+                var httpContext = _httpContextAccessor?.HttpContext;
                 // If session isn't enabled this will throw an exception so we check
-                var sessionFeature = _httpContextAccessor?.HttpContext?.Features.Get<ISessionFeature>();
+                var sessionFeature = httpContext?.Features.Get<ISessionFeature>();
                 return sessionFeature != null
-                    ? _httpContextAccessor?.HttpContext?.Session?.Id
+                    ? httpContext?.Session?.Id
                     : "0";
             }
         }

src/Umbraco.Web.BackOffice/AspNetCore/UmbracoBackOfficeServiceCollectionExtensions.cs

@@ -137,10 +137,11 @@ namespace Umbraco.Web.BackOffice.AspNetCore
             var ioHelper = new IOHelper(hostingEnvironment, globalSettings);
             var logger = SerilogLogger.CreateWithDefaultConfiguration(hostingEnvironment,
                 new AspNetCoreSessionIdResolver(httpContextAccessor),
-                () => serviceProvider.GetService<IRequestCache>(), coreDebug, ioHelper,
+                // need to build a new service provider since the one already resolved above doesn't have the IRequestCache yet
+                () => services.BuildServiceProvider().GetService<IRequestCache>(), coreDebug, ioHelper,
                 new AspNetCoreMarchal());
 
-            var backOfficeInfo = new AspNetCoreBackOfficeInfo(configs.Global());
+            var backOfficeInfo = new AspNetCoreBackOfficeInfo(globalSettings);
             var profiler = new LogProfiler(logger);
 
             Current.Initialize(logger, configs, ioHelper, hostingEnvironment, backOfficeInfo, profiler);

src/Umbraco.Web.UI.NetCore/Program.cs

@@ -1,6 +1,5 @@
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Hosting;
-using Serilog;
 using Umbraco.Core.Composing;
 
 namespace Umbraco.Web.UI.BackOffice
@@ -15,9 +14,8 @@ namespace Umbraco.Web.UI.BackOffice
         }
 
         public static IHostBuilder CreateHostBuilder(string[] args) =>
-            Host.CreateDefaultBuilder(args)                
+            Host.CreateDefaultBuilder(args)
                 .ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup<Startup>(); })
-                .UseUmbraco()
-                .UseSerilog();
+                .UseUmbraco();
     }
 }