Returns cannot be posted in the selected form

What causes this issue?

The return cannot be posted as expected, as the repayment request &V3&
has already been created for the associated payment (item &V2& in lot
&V1&).

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?

You can reverse the repayment request as long as it not has already
been disbursed. Otherwise you must post the return so that totally new
receivables are created.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.