Cause

In the project, a topology interruption point has the same DT as a "normal" interruption point.

Solution

1. Locate the topology interruption point in the routing path network using the Go to (graphic) function from the popup menu in the Message management dialog.
2. Call up the Properties <...> dialog of the topology interruption point, and enter a DT not yet assigned in the project in the Displayed DT field.
3. Then start a new check run.