title: UWP Assembly Error after Update to VS1015.3
body: <p>today I updated to Visual Studio 2015 Update 3. When I wanted to do a <code>Rebuild</code>, I encountered the following Error:</p>
  
  <p><a href="https://i.stack.imgur.com/UbrrX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UbrrX.png" alt="enter image description here"></a></p>
  
  <p>It reads:</p>
  
  <pre><code>Type universe cannot resolve assembly: System.Collections.NonGeneric, Version=4.0.0.0, Culture=neutral, PublicKeyToken=[...].
  </code></pre>
  
  <p>(I removed the <code>PublicKeyToken</code>) and</p>
  
  <pre><code>Cannot resolve Assembly or Windows Metadata file 'System.Collections.NonGeneric.dll'
  </code></pre>
  
  <p>This does not make any sense to me and it prevents me from building the whole thing. Also a <code>Clean Solution</code> and a manual deletion of the <code>bin</code> and <code>obj</code> folders doesn't make the error go away.</p>