Oct 16, 2014
(2 votes)

Problem with web.config after upgrade between MVC 4 and MVC 5, and and missing intellisense in Visual Studio.

This one will be a short blog post but I somehow a bit related to my last post about version of MVC and the 404 handlar from BVN Networks.

I recently created a new project and updated all nuget packages to the latest version of both EPiServer and Nugets from Microsoft.

After the upgrade I could not get the site to start and I got a strange error message. I also had problem with intellisense and none of the old ways of fixing the intellisense problem seemed to help.

The first error:

[A]System.Web.WebPages.Razor.Configuration.HostSection cannot be cast to 
Type A originates from 'System.Web.WebPages.Razor, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35' in the context 'Default' at location 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Web.WebPages.Razor\v4.0_2.0.0.0__31bf3856ad364e35\System.Web.WebPages.Razor.dll'. 
Type B originates from 'System.Web.WebPages.Razor, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35' in the context 'Default' at location 'C:\Users\MyName\AppData\Local\Temp\Temporary ASP.NET Files\root\63e7ff36\a1cb775d\assembly\dl3\8f568c18\9b7ddacf_d04dcf01\System.Web.WebPages.Razor.dll'.


This is casued by wrong versionnumbers in your config-files. This is easy to fix.

The fix:


        <assemblyIdentity name="System.Web.Mvc"
                          publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion=""
                         newVersion="" />
    <add key="webpages:Version"
         value="" />



The intellisense error for razorpages:

To fix the intellisense problem we need to update another web.config. This is located in the views-folder. If you look into this folder you will find out that you will need to fix other assembly versions as well:

In a view you will get the this problem with intellisens for helpers and types pages. Also the @model declaration is not working.


You need to change the following to target as below

    <sectionGroup name="system.web.webPages.razor"
                  type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
      <section name="host"
               type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
               requirePermission="false" />
      <section name="pages"
               type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
               requirePermission="false" />


To get the intellisense to work properly you also need to change to the latest version as below:

  <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />

If you need further assistance you can follow this post about upgrade an mvc project.


The old url did not work


Oct 16, 2014


Oct 22, 2014 09:01 AM

The URL to the asp.NET site does not seem to work.

Edit: Seems like they have withdrawn this page since I get the same page as a top hit on Google which results in a 404.

Eric Oct 22, 2014 09:34 AM

Ok, strange. Yes it looks like they have removed the page. I also get the top result in google for this page.. Maybe they have fixed the nuget update to actually fix all configs as well.

Edit: Found the page at

Jun 5, 2015 05:02 PM

thanks a lot eric, it soloved my issue.

Jun 23, 2015 10:51 AM

You are a lifesaver! Thanks a lot :)

Tibor Mohr
Tibor Mohr Feb 9, 2017 11:38 AM

Thanks :)

Eric Feb 9, 2017 01:54 PM

You are welcome :) 

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