title: Javascript Open Declaration (Ctrl+Click) broken after upgrading to Eclipse Mars
body: <p>After upgrading from Eclipse Luna to Mars, I found that the Ctrl+Click/F3 drill-down functionality (Open Declaration) does not work anymore, throwing an error:</p>
  
  <blockquote>
    <p>Problems opening an editor. See error log for more details.</p>
  </blockquote>
  
  <p>The following entries appear in the eclipse Error Log itself:</p>
  
  <blockquote>
    <p>Unexpected runtime error while computing a text hover (with a NullPointerException)<br>
    error during type inferencing (with a NullPointerException)<br>
    Internal Error (with InvocationTargetException caused by NullPointerException)</p>
  </blockquote>
  
  <p>Some additional observations:</p>
  
  <ul>
  <li>The problem occurs on a JavaScript-configured project which had no problems in Luna</li>
  <li>The problem <strong>does not</strong> occur on another JavaScript project, whose JS files are much less complicated (70KB in 5 files vs. 5MB in 19 files (excluding ExtJS libraries) in the problematic project)</li>
  <li>I installed Mars on top of Luna using the recommended update process (<a href="https://wiki.eclipse.org/FAQ_How_do_I_upgrade_Eclipse%3F" rel="nofollow">https://wiki.eclipse.org/FAQ_How_do_I_upgrade_Eclipse%3F</a>)
  
  <ul>
  <li>To ensure it is not due to something wrong during the upgrade, I also downloaded Eclipse Mars for Java EE Developers and installed it fresh.</li>
  <li>I did the same for the project, setting it up from scratch, to exclude the possibility some old Luna setting messing up with Mars</li>
  </ul></li>
  <li>Open Declaration, Open Implementation, etc. work in Java, only Javascript seems to be affected</li>
  </ul>
  
  <p>Does anybody have an idea if there is something I can do to fix this problem or it is an issue with Eclipse? (I couldn't find anything related in Eclipse's Bugzilla)</p>