SAP Message WB101 - Data on material & and material group & in customer & not found

Diagnosis
Material &v1& is listed for customer &v3& and is to be included in theassortment list. Material group &v2& to which this material is assignedhas, however, not yet been assigned to customer &v3&.

System Response
Material group data for the customer cannot be copied to the assortmentlist for material &v1&.

Procedure
Assign the material group to customer &v3&.