title: VS 2017 Metadata file '.dll could not be found
body: <p>I know there is another question with exact the same problem, but I went trough all those answers, and none helped me. :( (<a href="https://stackoverflow.com/questions/1421862/metadata-file-dll-could-not-be-found">This was the question.</a>)</p>
  
  <p>I just created a new ASP.NET MVC project and joined a few '.dll's in the solution. Now when I try to build the project I get the error message shown below on 3 of the 5 libraries.</p>
  
  <pre><code>Error   CS0006  Metadata file 'C:\Users\...\source\Database\bin\Debug\DataAccessLayer.dll' could not be found   Logic   C:\Users\...\source\Logic\CSC   1   Active
  
  Error   CS0006  Metadata file 'C:\Users\...\source\Logic\bin\Debug\Logic.dll' could not be found    PTS2-MVC    C:\Users\...\source\PTS2-MVC\CSC    1   Active
  
  Error   CS0006  Metadata file 'C:\Users\...\source\PTS2-MVC\bin\PTS2-MVC.dll' could not be found    PTS2-MVC.Tests  C:\Users\...\source\PTS2-MVC.Tests\CSC  1   Active
  </code></pre>
  
  <p>When I go to the bin\debug folder of that .dll, I see that it is empty, and the other .dll where I do not get an error message, is not empty. But I am clueless how to fix this or what I did to make this happen.</p>
  
  <p>The most common answer is to go to the <strong>properties</strong> of the <strong>solution</strong> and go to <strong>configuration</strong> and <em>uncheck</em> -> <em>apply</em> -> <em>check</em> and <em>apply</em> again, but that didn't work</p>