Reversed GR has already been invoiced - deletion of PO item not possible

What causes this issue?

The system has determined that there exists an invoice for the reversed
goods receipt.

System Response

The system could not set the deletion indicator in purchase order
&V1& item &V2&.

How to fix this error?

Please first post a credit memo for the goods receipt cancellation,
then manually set the deletion indicator to 'X' for the purchase order.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.