Cause
You use the PLC import interface Schneider Schneider Unity Pro: In the case of the M340 product line the PLC boxes for connecting the racks with each other are not contained in the import file.
Solution
Ensure that existing rack extensions are configured with the right hardware.
Note:
This module-specific message is generated by the importing of PLC data. Using a new check run (any desired scheme) it can be deleted from the message management dialog.