Message SAP WTADDI258 - & is not a valid customer for requesting the additionals IDoc via BAPI

Diagnosis Customer &V1& has requested an IDoc for an additional via BAPI. &V1& isnot allowed to call this data via BAPI, however. The system checks the customer number that you enter against the plant/customer entries in the document. The value you specify must match atleast one of these existing entries. System Response No additionals IDoc is generated. Procedure The CUSTOMER value you specified is probably not correct. Correct yourentries.