title: Can't set Android target after update sdk rev.21 in Eclipse
body: <p>After update Android SDK revision 21 for building application with Android 4.2. But now, I can't set Android Project Build target anymore.</p>
  
  <p>Steps in procedure:</p>
  
  <ol>
  <li><p>Updated Android SDK platform and platform tools to revision 21 via Android SDK manager.</p></li>
  <li><p>Updated ADT plugin for eclipse to revision 21.</p></li>
  <li><p>Restart Eclipse.</p></li>
  </ol>
  
  <p>This is Android entry in Eclipse Preferences.
  <img src="https://i.stack.imgur.com/HlaXs.png" alt="Android Preferences"></p>
  
  <p>This is my project's properties:
  <img src="https://i.stack.imgur.com/f87OG.png" alt="Project Properties"></p>
  
  <p>Thanks in advanced.</p>