Message SAP W_MD050 - More than one additional for item &2

Diagnosis
You are using an external Warehouse Management System (WMS). The itemV2 of inbound delivery v1 is assigned to more than one sls item. asa result, several final recipients (with the role 'UC') are linked tothis item. This is not permitted if you are using the external WMS inconjunction with cross-docking and prepacking.

System Response
This item is not seen as relevant for cross-docking with prepacking.