aspnet_compiler finding wrong version of System.Web.WebPages 1.0.0.0 instead of 2.0.0.0

Question

I have an ASP.NET MVC4 project which compiles fine in VS2010. For deployment purposes I run a Nant script which attempts to precompile the website using aspnet_compiler.exe but I keep running into an assembly reference issue with System.Web.WebPage

error CS1705: Assembly 'System.Web.Mvc, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' uses 'System.Web.WebPages, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' which has a higher version than referenced assembly 'System.Web.WebPages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'

I also have the following assembly bindings in my web.config:

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
        <dependentAssembly>
            <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
            <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
        </dependentAssembly>
        <dependentAssembly>
            <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
            <bindingRedirect oldVersion="0.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
        </dependentAssembly>
        <dependentAssembly>
            <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
            <bindingRedirect oldVersion="0.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
        </dependentAssembly>
        <dependentAssembly>
            <assemblyIdentity name="System.Web.WebPages.Razor" publicKeyToken="31bf3856ad364e35" />
            <bindingRedirect oldVersion="0.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
        </dependentAssembly>
    </assemblyBinding>
</runtime>

and my csproj has the following reference:

<Reference Include="System.Web.WebPages, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
  <Private>True</Private>
 <HintPath>..\packages\AspNetWebPages.Core.2.0.20126.16343\lib\net40\System.Web.WebPages.dll</HintPath>
</Reference>

Answer 1

I solved this problem by explicitly referencing the 2.0 assembly in Web.config. I suppose that for some reason, the ASP.NET compiler (in my case when running MvcBuildViews), uses the old 1.0 assembly first, if it is found.

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <!-- … -->
  <system.web>
    <!-- … -->
    <compilation debug="true" targetFramework="4.0">
      <assemblies>
        <add assembly="System.Web.Mvc, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL" />
        <add assembly="System.Web.Abstractions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
        <add assembly="System.Web.Routing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
        <add assembly="System.Web.WebPages, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL" />
      </assemblies>
    </compilation>
    <!-- … -->
  </system.web>
  <!-- … -->
</configuration>

BTW: It looked like this problem occurred for the first time after I added a 3rd party ASP.NET MVC 3.0 component. That component works fine through the assembly binding, but it may be the reason why the ASP.NET compiler tries to load the 1.0 web pages first.

Answer 2

We had similar problem.

We are now using Visual Studio 2012 for developing and when we converted a 2010 project to 2012 and tried to deploy that, ASP.NET was requiring 2.0.0.0 instead of 1.0.0.0.

After some investigation I saw that the project was not referencing a specific version of System.Web.WebPages, so after upgrading to VS 2012 it was finding the 2.0.0.0 version.

If you remove the reference from your project and then re-add the specific version from the GAC, it works correctly.

Answer 3

For us, the problem was an old copy of the relevant DLL in the _bin_deployableAssemblies folder. Deleting this got us correctly configured with the 2.0 version.