Invoice item &1/&2 is not categorized as a correction or reversal invoice

What causes this issue?

You have not assigned an invoice type to the line item you want to
correct or reverse.

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?

Assign an invoice identifier
to the line item you want to correct or reverse in the
<DS:REPN.RFREXCCORRRAIV>Assign Correction/Reversal Identifier to Invoice
</> report.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.