title: Can't connect interactions in interaction overview diagram in EA
body: <p>I have a problem with the Interaction overview diagram in EA.
  I cannot connect any control nodes to InteractionUse element I added to the diagram. Or even between two InteractionUse elements.</p>
  <p>I'm getting the following error:
  <em>The requested connection is not UML compliant.</em></p>
  <p>Can anybody give me some advice on this?</p>
  <p>Here are some images to demonstrate the problem:</p>
  <p><a href="https://i.stack.imgur.com/GsVjG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GsVjG.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/iaZYl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iaZYl.png" alt="enter image description here" /></a></p>