title: Cannot delete / modify some workitems after deleting some others in VSTS
body: <p>We have been deleted some stuff from one VSTS project due to some internal reorganization. After doing it we found that some workitems cannot be modified / deleted anymore, if we try to delete them we get a:</p>
  
  <blockquote>
    <p>Failed to delete work item: 47420. Error Details: TF401232: Work item 53559 does not exist, or you do not have permissions to read it.</p>
  </blockquote>
  
  <p>47420 is the WorkItem that I have tried to delete, 53559 is a deleted workitem that was a child of this one.</p>
  
  <p>If I open the WorkItem 47420 I see under <strong>Related Work</strong> the error: <em>Work item not found or no permission to access it.</em></p>
  
  <p>If I delete the link and save the change I get again:</p>
  
  <blockquote>
    <p>TF401232: Work item 53559 does not exist, or you do not have
    permissions to read it.</p>
  </blockquote>
  
  <p>Any ideas? This is happening with quite a few elements ...</p>