title: visual studio 2017 errors are not shown
body: <p>I'm using Visual studio 2017 Community v14.0.25431.01 Update 3 and errors are not shown. As you can see in VS 2015 i can see errors underlined but not in VS2017.</p>
  
  <p>VS2017 Exemple :</p>
  
  <p><a href="https://i.stack.imgur.com/YLbJl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/YLbJl.png" alt="VS2017 exemple"></a></p>
  
  <p>VS2015 Exemple :</p>
  
  <p><a href="https://i.stack.imgur.com/CFHtJ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/CFHtJ.png" alt="VS2015 exemple"></a></p>