title: Navigation Preview/Editor not showing
body: <p>I updated android studio:</p>
  
  <p><a href="https://i.stack.imgur.com/DdoV7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DdoV7.png" alt="enter image description here"></a></p>
  
  <p>And now I cant see navigation preview, only the xml.</p>
  
  <p><a href="https://i.stack.imgur.com/xZQ5U.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xZQ5U.png" alt="enter image description here"></a></p>
  
  <p>It not appear preview or design option.</p>
  
  <p>Any ideas? Thank you very much!</p>