SAP Message V2227 - No update of sales order &1 from purchase order (error &2 &3)

Diagnosis
You want to create or change a purchase order. The system attempted toupdate the relevant sales order item(s) in the sales order &V1&. Duringthis update, error message &V2& &V3& was triggered.

System Response
You cannot create or change the purchase order.

Procedure
Try and remove the cause for the error message &V2& &V3& in the salesorder, then attempt to create or change the purchase order again.