title: VS 2015 build error: PE image does not contain metadata
body: <p>While building a c# class library (.NET 4.0) using VS 2015 I am getting the error: PE image does not contain metadata.</p>
  
  <p>I tried the obvious stuff which doesn't help:
  1. perform clean entire solution
  2. REstart Visual Studio and rebuild all</p>
  
  <p>strange thing is that the even though the DLL builds and works, this annoying error is still staying in the error window of the build output.</p>
  
  <p>The complete error reads:
  Error while reading c:/XX/xxx/DEBUG/mylib.dll :  PE image doesn't contain metadata.</p>
  
  <p>Any ideas?</p>
  
  <p>EDIT:  after  I restarted my computer the error went away.  This is not really a solution, so I did not answer my own question, but at least it works around an annoying error.</p>