title: Compilation error at runtime from Microsoft.AspNet.WebApi.HelpPage version 4.0.30506
body: <p>I am getting the following error when I try to use version 4.0.30506 (unfortunately we are tied to this version of ASP.NEt Web API for now) of the Microsoft.AspNet.WebApi.HelpPage nuget package. I am using Windows 7 and .NET 4.5.</p>
  
  <pre><code>Compilation Error
  
  Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. 
  
  Compiler Error Message: CS0012: The type 'System.Object' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
  
  Source Error:
  
  
  Line 11: 
  Line 12:     // Group APIs by controller
  Line 13:     ILookup&lt;string, ApiDescription&gt; apiGroups = Model.ToLookup(api =&gt; api.ActionDescriptor.ControllerDescriptor.ControllerName);
  Line 14: }
  Line 15: 
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/FxOi6.png" alt="enter image description here"></p>
  
  <p>As far as I can see I have all the correct references for this to work. I have tried looking for a System.Runtime assembly as it suggests, but I can't find it on my system. I have added using statements to the top of Index.cshtml, but with no affect.</p>
  
  <pre><code>@using System
  @using System.Runtime
  </code></pre>
  
  <p>Any suggestions of what is causing this error?</p>