SAP Message 88756 - Error in billing item &1/&2: material number is initial

Diagnosis
No material number could be determined for the recycling declarationfrom billing item &V2& for document &V1&.

System Response
The system can not process the billing item.

Procedure
Please check the billing item &V1& / &V2& and, if relevant, the settingin general REA Customizing for "Field material number" in the section"Control of Declaration/Origin Movement Data".