title: All quality profiles have no rules when SonarQube is upgraded to 5.4
body: <p>We are currently running a production server at version 5.1.2 which we are planning to upgrade.</p>
  
  <p>Tests have shown that upgrading to 5.3 works as expected.</p>
  
  <p>However, upgrading from 5.1.2 -> 5.4 or 5.1.2 -> 5.3 -> 5.4 results in all quality profiles from the 5.1.2 instance becoming empty - no rules assigned at all.</p>
  
  <p>Worse, backing up the rules and attempting to restore them fails silently.</p>
  
  <p>Has anyone else experienced this? Is there a work-around?</p>
  
  <p>Thanks in advance.</p>