SAP Message VSB012 - Sales document is currently locked by user &1

Diagnosis
Sales document &V2& is or was blocked at the stage when the salesdocument was processed during the processing step. The user who islocking or who has locked the the sales document was &V1&.
It is possible that the delivery is or has been simultaneously processedby another processing step, or by another parallel process.

System Response
The processing step is terminated as parallel processing of a salesdocument in different processes can lead to inconsistencies.

Procedure
Wait until the delivery is no longer blocked by another user, and thenrestart the processing step again.