title: Unable to execute dex: Multiple dex files define
body: <p>I know this question has been asked  here a few times before. But i haven't seen any possible solution yet.
  Before i make the project 'Run as Android Application' , if i do not clean it, i receive the following error and have to restart Eclipse ... and clean again.</p>
  
  <pre><code>Conversion to Dalvik format failed: Unable to execute dex: Multiple dex files define
       Lcom/jstun/core/attribute/MessageAttributeInterface;
  </code></pre>
  
  <p>com.jstun.core... is a part of my src folder, of course i can't remove it. And even if i remove that package, another package will show up as an error like:</p>
  
  <pre><code>Unable to execute dex: Multiple dex files define
       Landroid/support/v4/app/ActivityCompatHoneycomb;
  </code></pre>
  
  <p>I've seen this error since updating to ADT 15, i'm using Eclipse Galileo on Ubuntu
  Do you have any idea? Thanks for any reply!</p>