Message SAP WV657 - Account group &1 for competitor &2 is not allowed

Diagnosis
Competitors are modeled as customers. When you create the customerdata, you should use an account group that is flagged as a "Competitoraccount group".
The account group &V1& for competitor &V2& is not a competitor accountgroup, however.

Procedure
Check the customer data for competitor &V2& and change the accountgroup if necessary.