Symptoms

When you modify the existing Source/Target node of a Facility to other Node in the same site
 by adding a gap segment between the 2 elements. The thus changed Facility becomes corrupt.

While setting the new node as Source/Target, you have right-clicked on the square surrounding Node ie on the site frame but not on the node frame. So here, you should be able to see a Node to the left and a dark square to the right of the design (Site). In the right-side you are not be able to see the node icon.
If you try to access the facility then the Client crashes.

Cause