title: Use case diagram "details" tab says "No Details"
body: <p>I would like to add some preconditions to my use case but as soon as i enter my use case (description and all other tabs) the "Details" tab says "No Details". only one use case has an option to add preconditions and actually see the "Details" tab.
  How can i make the "Details" tab visible?
  thanks :)</p>