Razor 2 to Razor 3 MVC 5

Question

I've been working on an MVC 4 solution, and I've been trying to upgrade it to MVC 5. I've followed the steps outlined here.

I've followed it, and now whenever I run the MVC Application, it gives me this error message:

[A]System.Web.WebPages.Razor.Configuration.HostSection cannot be cast to 
[B]System.Web.WebPages.Razor.Configuration.HostSection. 

Type A originates from 
'System.Web.WebPages.Razor, Version=2.0.0.0, 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=3.0.0.0, Culture=neutral, 
PublicKeyToken=31bf3856ad364e35' in the context 'Default' at location 
'C:\Users\User\AppData\Local\Temp\Temporary ASP.NET 
Files\root\665ac028\de53a189\assembly\dl3\c2c0a4b5\56e8099e_40e0ce01\System.Web.WebPages.Razor.dll'.

Does anyone know how this could have originated? or how it can be solved? I've looked around thus far? I've tried changing the web.config files, with no avail...

Solution 1

In your Web.config(-s) make sure assemblyBinding contains the proper version for the assembly System.Web.WebPages.Razor and System.Web.Mvc.

<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
  <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages.Razor" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0"/>
  </dependentAssembly>

  <dependentAssembly>
    <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
    <bindingRedirect oldVersion="1.0.0.0-5.0.0.0" newVersion="5.0.0.0" />
  </dependentAssembly>
</assemblyBinding>

And make sure that razor sectionGroup in ConfigSections reference latest versions as well:

<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>

Solution 2

Check for version in web.config. If it again gives an error, try to clean the solution and rebuild it. Also check for project's Bin folder, removes old references from bin folder and rebuild the project solution.

Comments

[Dylan Corriveau]

in the binding redirect, MVC has 0-5, new version 5, and razor has 1-3 new version 3

[Dylan Corriveau]

You were correct. Although I did restart the application (I wasn't very far in it, so I just made an MVC 5 project and ported it), I noticed the issue was that in the second web config after the fact (the one inside of views)

[Dima]

Exactly, because you may have configs in literally any part of the project, it's essential to look through/correct all of them

[Dylan Corriveau]

thanks Dima :). How many web.config's are there usually, just the two, right? or does that depend?

[Dima]

Default MVC website template has 2 configs: one in website root directory and another one in Views. Mvc team plays with templates changing them from version to version, so it's better to use file search to be sure you haven't missed any.

[Rodolpho Brock]

This works stackoverflow.com/questions/17454852/…

[ManirajSS]

what we have to do dependentAssembly not at all have System.Web.WebPages.Razor ???

[Howiecamp]

@Dima - Would the public key token have to change since the version of the library changed?

[Dima]

@Howiecamp they all signed with the same private Microsoft's key, which haven't been changes for a long time (if ever). So no, public key token wouldn't change with new library version.

[Arvind Dhasmana]

@Dima I changed my project from Framework 4.0 to 4.5.1 and install the MVC 5.2.3 and faced this same issue. I follow your answer and found that only following was missing in main web.config, <dependentAssembly> <assemblyIdentity name="System.Web.WebPages.Razor" publicKeyToken="31bf3856ad364e35" /> <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0"/> </dependentAssembly>

[Gonzalo Méndez]

Worked perfectly to me. Thanks dude!