title: Visual studio 2019 go to definition and Intellisense not working
body: <p>I have noticed a weird issue with Visual Studio 2019 v16.0.1 the IntelliSense about "Using directive is unnecessary" normally grey is missing and type reference suggestion for missing using is not working.</p>
  
  <p>I also tried with Visual Studio 2019 Preview but no luck.</p>
  
  <p>I have tried the following:</p>
  
  <ol>
  <li>deleted .vs folder and restarted.</li>
  <li>Reinstalled Visual Studio </li>
  <li>Reset settings via import and export setting under tools</li>
  </ol>
  
  <p>Any other suggestions will be appreciated.</p>