Terms of payment & in PO & differ from those entered

What causes this issue?

You entered the terms of payment of the invoice. Other terms of payment
were, however, agreed in the purchase order.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check that the terms of payment you entered were correct and also the
allocation you made.
To find out the terms of payment in the purchase order, delete your
entry in the <LS>terms of payment</> section and press ENTER. The
system suggests the agreed terms of payment from the purchase order.

Error message extract from SAP system. Copyright SAP SE.