title: Xap packaging failed. Object reference not set to an instance of an object
body: <p>I'm getting this error message on my PC when I try to build my Windows Phone app:</p>
  
  <pre><code>Xap packaging failed. Object reference not set to an instance of an object
  </code></pre>
  
  <p>I'm using Dropbox. On my laptop, It works perfectly fine and I can debug etc...On my PC however, I can't.</p>
  
  <p>I tried many things such as:</p>
  
  <ul>
  <li>Delete <strong>obj/Debug</strong> Folder</li>
  <li>Check for files which are missing on the <strong>Solution Explorer</strong></li>
  </ul>
  
  <p>So far, nothing has helped.</p>
  
  <p>Any idea how I can fix this?</p>