title: Can't delete backend service in GCE
body: <p>I want to free up some backend services quotas.  In order to do so, I believe I first have to delete the instance group.  However, when I tried to delete the instance group that uses the service, I get the following message:</p>
  
  <blockquote>
    <p>The deletion of the instance group failed. Error: An unknown error has
    occurred in Compute Engine: "undefined". Error code: "undefined"</p>
  </blockquote>
  
  <p>I have also tried to just delete the backend service but it will spring up another one.  In addition, I have tried to delete the load balancer associating the service and that fail also.  Any thoughts?</p>