Cause

The cable has more than one N-conductor.

Solution

Change the potential type at the connection points of the functions that lead in N-wires appearing several times in the cable.

1. Call up the respective property dialog at the functions that are the source and / or target of the cable.
2. For each function bring the Symbol / function data tab to the front, and click the [Logic] button.
3. In the Connection point logic dialog at the function connection points check the value in the Potential type field.
4. Then select a different potential type, for example "Undefined", at the function connection points with the value "N" assigned several times.
5. Confirm your entries.
6. Update the connections.
7. If required, start a new check run.