diff --git a/src/Umbraco.Core/Configuration/GlobalSettings.cs b/src/Umbraco.Core/Configuration/GlobalSettings.cs
index bd3cc9c74a..cf0dd1e7d0 100644
--- a/src/Umbraco.Core/Configuration/GlobalSettings.cs
+++ b/src/Umbraco.Core/Configuration/GlobalSettings.cs
@@ -234,16 +234,16 @@ namespace Umbraco.Core.Configuration
             var xml = XDocument.Load(fileName, LoadOptions.PreserveWhitespace);
 
             var appSettings = xml.Root.Descendants("appSettings").Single();
-
             var setting = appSettings.Descendants("add").FirstOrDefault(s => s.Attribute("key").Value == key);
+
             if (setting != null)
+            {
                 setting.Remove();
-
-            xml.Save(fileName, SaveOptions.DisableFormatting);
-            ConfigurationManager.RefreshSection("appSettings");
+                xml.Save(fileName, SaveOptions.DisableFormatting);
+                ConfigurationManager.RefreshSection("appSettings");
+            }
         }
 
-
         private static string GetFullWebConfigFileName()
         {
             var webConfig = new WebConfigurationFileMap();
diff --git a/src/Umbraco.Web.UI/web.Template.Debug.config b/src/Umbraco.Web.UI/web.Template.Debug.config
index a28a069e17..f9dcde4d78 100644
--- a/src/Umbraco.Web.UI/web.Template.Debug.config
+++ b/src/Umbraco.Web.UI/web.Template.Debug.config
@@ -51,6 +51,13 @@
         <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
       </dependentAssembly>
 
+      <dependentAssembly xdt:Transform="Remove"
+												 xdt:Locator="Condition(_defaultNamespace:assemblyIdentity[@name='System.Web.WebPages.Razor']])"/>
+      <dependentAssembly xdt:Transform="Insert">
+        <assemblyIdentity name="System.Web.WebPages.Razor" publicKeyToken="31bf3856ad364e35" />
+        <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
+      </dependentAssembly>
+
     </assemblyBinding>
   </runtime>
 
diff --git a/src/Umbraco.Web/umbraco.presentation/install/steps/Definitions/Database.cs b/src/Umbraco.Web/umbraco.presentation/install/steps/Definitions/Database.cs
index a11e3be5da..ccd713e78b 100644
--- a/src/Umbraco.Web/umbraco.presentation/install/steps/Definitions/Database.cs
+++ b/src/Umbraco.Web/umbraco.presentation/install/steps/Definitions/Database.cs
@@ -14,7 +14,7 @@ namespace umbraco.presentation.install.steps.Definitions
 
         public override string Name
         {
-          get { return "Database"; }
+            get { return "Database"; }
         }
 
         public override string UserControl
@@ -22,7 +22,7 @@ namespace umbraco.presentation.install.steps.Definitions
             get { return SystemDirectories.Install + "/steps/database.ascx"; }
         }
 
-        
+
         public override bool MoveToNextStepAutomaticly
         {
             get
@@ -34,22 +34,10 @@ namespace umbraco.presentation.install.steps.Definitions
         //here we determine if the installer should skip this step...
         public override bool Completed()
         {
-            bool retval = false;
-            try
-            {
-                var configuredVersion = new Version(Umbraco.Core.Configuration.GlobalSettings.ConfigurationStatus);
-                var targetVersion = UmbracoVersion.Current;
-
-                retval = targetVersion > configuredVersion;
-
-            } catch {
-                // this step might fail due to missing connectionstring
-                return false;
-            }
-
-            return retval;
+            var configuredVersion = new Version(Umbraco.Core.Configuration.GlobalSettings.ConfigurationStatus);
+            var targetVersion = UmbracoVersion.Current;
+            
+            return targetVersion < configuredVersion;
         }
-
-        
     }
 }
\ No newline at end of file
diff --git a/src/Umbraco.Web/umbraco.presentation/install/utills/p.aspx.cs b/src/Umbraco.Web/umbraco.presentation/install/utills/p.aspx.cs
index eef79a6cc6..d44285e93d 100644
--- a/src/Umbraco.Web/umbraco.presentation/install/utills/p.aspx.cs
+++ b/src/Umbraco.Web/umbraco.presentation/install/utills/p.aspx.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Configuration;
 using System.Web.Script.Serialization;
 using System.Web.Script.Services;
 using System.Web.Services;
@@ -60,9 +61,18 @@ namespace umbraco.presentation.install.utills
 
             var result = ApplicationContext.Current.DatabaseContext.CreateDatabaseSchemaAndDataOrUpgrade();
             
-            // Remove legacy umbracoDbDsn configuration setting if it exists
-            Umbraco.Core.Configuration.GlobalSettings.RemoveSetting(Umbraco.Core.Configuration.GlobalSettings.UmbracoConnectionName);
-            
+            // Remove legacy umbracoDbDsn configuration setting if it exists and connectionstring also exists
+            if (ConfigurationManager.ConnectionStrings[Umbraco.Core.Configuration.GlobalSettings.UmbracoConnectionName] != null)
+            {
+                Umbraco.Core.Configuration.GlobalSettings.RemoveSetting(Umbraco.Core.Configuration.GlobalSettings.UmbracoConnectionName);
+            }
+            else
+            {
+                var ex = new ArgumentNullException(string.Format("ConfigurationManager.ConnectionStrings[{0}]", Umbraco.Core.Configuration.GlobalSettings.UmbracoConnectionName), "Install / upgrade did not complete successfully, umbracoDbDSN was not set in the connectionStrings section");
+                LogHelper.Error<p>("", ex);
+                throw ex;
+            }
+
             var js = new JavaScriptSerializer();
             var jsonResult = js.Serialize(result);
             return jsonResult;
diff --git a/src/umbraco.businesslogic/BasePages/BasePage.cs b/src/umbraco.businesslogic/BasePages/BasePage.cs
index c6655d76a6..cc4148a0da 100644
--- a/src/umbraco.businesslogic/BasePages/BasePage.cs
+++ b/src/umbraco.businesslogic/BasePages/BasePage.cs
@@ -311,9 +311,18 @@ namespace umbraco.BasePages
 
         private void DeleteLogin()
         {
-            SqlHelper.ExecuteNonQuery(
+            // Added try-catch in case login doesn't exist in the database
+            // Either due to old cookie or running multiple sessions on localhost with different port number
+            try
+            {
+                SqlHelper.ExecuteNonQuery(
                 "DELETE FROM umbracoUserLogins WHERE contextId = @contextId",
                 SqlHelper.CreateParameter("@contextId", umbracoUserContextID));
+            }
+            catch (Exception ex)
+            {
+                LogHelper.Error<BasePage>(string.Format("Login with contextId {0} didn't exist in the database", umbracoUserContextID), ex);
+            }
         }
 
         private void UpdateLogin()