How To Fix TU526 - Reversal is not possible; billing documents still exist for contract &2

SAP Error Message - Details

• Message type: E = Error

• Message class: TU - Billing/Scheduling/Budget Billing

• Message number: 526

• Message text: Reversal is not possible; billing documents still exist for contract &2

What causes this issue?

You have tried to reverse a final bill for contract &V1&. This final
bill was generated in a supplier change. You can only reverse the final
bill, when no more valid billing documents exist for subsequent
contract &V2&.
A check determined that at least one unreversed billing document exists
for contract &V2&.

System Response

INCLUDE ISU_VERARB OBJECT DOKU ID TX

How to fix this error?

Reverse all billing documents for contract &V2&.
Reverse the final bill for contract &V1&.

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.