Unable to create '/git/index.lock': File exists - but it doesn't
<p>I'm getting this message when trying to rebase interactively using source tree.</p>

<pre><code>If no other git process is currently running, this probably means a
git process crashed in this repository earlier. Make sure no other git
process is running and remove the file manually to continue.
</code></pre>

<blockquote>
  <p>fatal: Unable to create 'X:/sources/project/.git/index.lock': File
  exists.</p>
</blockquote>

<p>The problem is that <strong>X:/sources/project/.git/index.lock</strong> doesn't exist</p>

<p>All the other solutions on SO didn't work for me since they all say to remove this file.</p>