title: App build.gradle error
body: <p>This is happening after I launched AVD for app test, and it was starting android OS. few seconds later, my computer( using Mac) was restarted by causing error Android Studio. After the happening, my Android Studio is strange.</p>
  
  <ul>
  <li>It was working well, but it suddenly happened.</li>
  <li>Android Studio does not still work after I used a Clean Project ,and it can't recognize things such as <code>R.</code> , all those methods.</li>
  </ul>
  
  <p>Thank you :) </p>
  
  <p>I attached the screenshot for your understanding. </p>
  
  <p><a href="https://i.stack.imgur.com/4yOcL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4yOcL.png" alt="Android Studio Error"></a></p>