title: Can't build android project because ActionBarActivity cannot be resolved to a type
body: <p>I'm following the training on the developer.android.com site and when I arrived at the Building your first app / Starting another activity section I failed:</p>
  
  <p>I've added the android-support-v7-appcompat library according to this site describes: <a href="http://developer.android.com/tools/support-library/setup.html#libs-with-res" rel="nofollow noreferrer">http://developer.android.com/tools/support-library/setup.html#libs-with-res</a></p>
  
  <p>Where I select the libraries for an android project (Properties of the project / Android / Library) I clicked the add button, selected the project library (first picture), and after I pressed ok the project didn't build.</p>
  
  <p>Before (everything is ok)
  <img src="https://i.stack.imgur.com/BgroJ.png" alt="Before click ok"></p>
  
  <p>After
  <img src="https://i.stack.imgur.com/eZBfS.png" alt="Somehow it failed when I ok&#39;d the window."></p>
  
  <p>Before all this... I was somehow able to build the project, press the Play, but it unfortunately stopped (crashed) on my device immediately after starting. And the console said:</p>
  
  <pre><code>[2014-07-23 15:06:45 - android-support-v7-appcompat] Could not find android-support-v7-appcompat.apk!
  </code></pre>
  
  <p>and that was the point when I started investigating the problem... yet unsuccessfully.</p>
  
  <p>My question is, why "deactivating" the library after I check again?</p>