title: Cannot install module on openERP
body: <p>I have a problem in using openERP.</p>
  
  <p>I uninstalled the base kanban module by accident, but I've succeeded to install it back:</p>
  
  <p>But then my installed project management got uninstalled automatically, and now I can't install it back. It says:</p>
  
  <pre><code>"Constraint Error
  
   You can not have two users with the same login !"
  </code></pre>
  
  <p>I've been looking for solutions through Google but I haven't found any.</p>