SAP Message 06727 - A different source of supply is the fixed source for this date

Diagnosis
The source list specifies a differentsource of supply (vendor, outline agreement, orplant) for the material for this date than the vendor entered. Thismeans that the material is to be procured only from the source shown inthe source list at this point in time.
The source has the number:
V1 v2 v3 v4

Procedure
Check the source list to establish whether the fixed source representsa feasible procurement option for this purchase order:
Display source list