SAP Message >2534 - Clarification document &1 for document &2 could not be reversed

Diagnosis
You attempt to post a return for a payment that was made by check lot.This payment is under review, and was already clarified.
The return processing attempted to reverse this clarification document,but was unsuccessful.

System Response
It is not possible to post the return.

Procedure
Reverse the review manually and then repost the return inpostprocessing.