Base UoM of delivery item is not = purchase order item qty. schedule.

What causes this issue?

The base unit of measure in the quantity schedule of the purchase order
item is different from the delivery item.
The base units of measure must be the same.

System Response

The system will not accept the assignment of this purchase order item.

How to fix this error?

Please use another purchase order item or change the delivery date.

Error message extract from SAP system. Copyright SAP SE.