title: Cannot Resolve Symbol 'R' Android Studio 3.0
body: <p>My app was working normally. When I went to sleep I left the PC on and the next morning I found this error in the <code>R: can not resolve symbol</code> ... Try everything, build, even from the gradle and nothing works</p>
  
  <p>When I try to clean up, it throws me a lot of errors, the same is with build and build APK (s)</p>
  
  <p><a href="https://i.stack.imgur.com/2FDXE.png" rel="nofollow noreferrer">A big lot of errors</a></p>