Cause

The connections of the planned cable in the multi-line representation are not defined uniquely, because the properties "Color / number" and / or "Pair index" have identical values for at least two cable connections. Thus, the cable could not be routed in the topology.

Solution

1. Locate the multi-line cable in the project by using the Go to (graphic) functionality from the popup menu in the Message management dialog.
2. Call up the Properties <...> dialog for all connections of the cable, and compare the values in the fields Color / number and/or Pair index.
3. If two or more connections have identical values with respect to the above properties, modify them. Make sure to assign to each connection a unique value for the respective property.
4. Update the connections.
5. Route the cable through the routing path network again.
6. If required, start a new check run.