title: can't resolve AppCompatActivity
body: <p>After renaming application package name, Android Studio displayed this error <code>can't resolve symbol AppCompatActivity</code> </p>
  
  <p><strong>Things I tried:</strong> </p>
  
  <ul>
  <li>Clean project </li>
  <li>Clean Android Studio cache</li>
  <li>Clean Gradle cache</li>
  <li>Re-installed IDE</li>
  <li>File-> Invalidate cache/restart </li>
  </ul>
  
  <p>But nothing really helped. The project build successfully, but I can not use syntax highlighting. </p>
  
  <p>I used <code>com.android.support:appcompat-v7:23.1.1</code> </p>
  
  <p><strong>Screenshots</strong></p>
  
  <p><a href="https://i.stack.imgur.com/GIfQw.png" rel="noreferrer"><img src="https://i.stack.imgur.com/GIfQw.png" alt="BaseActivity"></a></p>
  
  <p><a href="https://i.stack.imgur.com/7s9uk.png" rel="noreferrer"><img src="https://i.stack.imgur.com/7s9uk.png" alt="Build gradle file"></a></p>