title: .NET 3.5 to .NET 4.5.1 migration issues
body: <p>Some background: I recently upgraded from VS2008 to VS2013 which went off without a hitch. I then updated the target framework for each of the solutions in my project (A web portal, three services, a Data Access Layer, and report library). After changing the framework, I got this error:</p>
  
  <pre><code>Error   174 Assembly 'DAL', Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' uses 'System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=[token]' which has a higher version than referenced assembly 'System.Data.Entity, Version=3.5.0.0, Culture=neutral, PublicKeyToken=[token]'       
  </code></pre>
  
  <p>So I updated the reference in our Web.Config file to 4.0.0.0:</p>
  
  <pre><code>&lt;add assembly="System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=[token]"/&gt;
  </code></pre>
  
  <p>This fixed the immediate error (of course) but now I'm faced with 8 fresh errors which are all of this nature: </p>
  
  <pre><code>Error   174 The type 'System.Data.Objects.ObjectContext' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=[token]'.
  </code></pre>
  
  <p>This is thrown when I call </p>
  
  <pre><code>DAL.App_Data.MyEntities me = new DAL.App_Data.MyEntities();
  </code></pre>
  
  <p>I have checked, and both the DAL and the project it is being called from have references to  System.Data.Entity of version 4.0.0.0. DAL has it in the project file and the other has it in the web.config file. </p>