Cause

A connection between two different bus systems was determined. For example a bus port of the "PROFIBUS" bus system was connected to a bus port of the "Ethernet" bus system. The placeholders '<x>' and '<y>' display the respective bus system.

Solution

1. Locate the bus ports connected to each other in the schematic by using the functionalities Go to (graphic) and Go to (2nd coordinate), which the popup menu of the Message management dialog offers you.
2. Call up the Properties <...> dialog at the two bus ports.
3. Bring the Bus data tab to the front.
4. Check the setting for both bus ports respectively in the Bus system field.
5. Select the same bus system at both bus ports and close the Properties <...> dialog with [OK].
6. Update the connections.
7. If required, start a new check run.