title: Error obtaining UI hierarchy in UIAutomator
body: <p>I'm unable to take a screen-shot from the UIAutomator tool. When i am running UIAutomator from the command line (on Ubuntu), I'm getting the following error in the tool:</p>
  
  <pre><code>Error obtaining UI hierarchy 
  Reason Error while parsing UI hierarchy
  XML file: Invalid ui automator hierarchy file
  </code></pre>
  
  <p>And, on the command line, a "<strong>null rootnode after parsing</strong>." message.</p>
  
  <p>Any suggestions would be really appreciated.</p>