I had the same problem,
I eventually solved it by following the advice here.
And adding the following to my web.config
<?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>