Diagnosis
You have already processed an intermediate document (IDoc) forexternal document number &V1&. Either the IDoc has been submitted morethan once or there are several IDocs for the same external documentnumber.

System Response
The system does not process an IDoc if it does not have a uniqueexternal number. If the system allowed several IDocs for one externalnumber, you would not be able to determine a referenced document forcorrection documents, for example.

Procedure
Change the external document number in the IDoc, or ask the customer tosend a correct IDoc.