title: Error "The type or namespace name 'DotNetOpenAuth' could not be found" in VS2013 but not VS2012
body: <p>I have a ASP.NET MVC 3 project, which uses DotNetOpenAuth, retrieved via NuGet. Package restore is enabled. The project uses .NET 4 (the full profile, not client).</p>
  
  <p>In Visual Studio 2012, the project compiles and runs fine.</p>
  
  <p>In Visual Studio 2013, I get the following error:</p>
  
  <blockquote>
    <p>The type or namespace name 'DotNetOpenAuth' could not be found (are you missing a using directive or an assembly reference?)</p>
  </blockquote>
  
  <p>The DLLs are successfully restored to the <code>packages</code> folder, and are also correctly copied to the <code>bin</code> folder of the website project. All appropriate <code>using</code>s have been added. Each time I have tested a change from a clean working directory. All of the other projects in the solution compile fine. The assembly references look like this in the <code>Website.csproj</code> file:</p>
  
  <pre><code>&lt;Reference Include="DotNetOpenAuth.Core, Version=4.3.0.0, Culture=neutral, PublicKeyToken=2780ccd10d57b246, processorArchitecture=MSIL"&gt;
    &lt;HintPath&gt;..\..\packages\DotNetOpenAuth.Core.4.3.1.13153\lib\net40-full\DotNetOpenAuth.Core.dll&lt;/HintPath&gt;
  &lt;/Reference&gt;
  </code></pre>
  
  <p>How can I solve this?</p>