Message SAP WT122 - Material &1 in plant &2 is blocked by user &3

Diagnosis
You called up the replenishment data for material &v1& in plant &V2&for processing. This data is currently being processed by user &V3& andis therefore blocked.

System Response
No changes were made.

Procedure
Check if your entries are correct. IF they are, try again later orcontact user &V3&.