User is trying to increase the quantity of a PO and is receiving error of Improper commodity code. I have troubleshooted this issue for the user and was able to confirm that the commodity code used in the PO and the Purchase requisition is the same that is setup in the material master for this material. Also verified the PIR for this material and it also has the same commodity code as the one used for this PO. Even though this information is correct the system continues to generate this error. What am I missing? Please help SAP Gurus.