Settlement data (rebate income) inconsistent (internal error)

What causes this issue?

The settlement data for a condition record belonging to rebate
arrangement &V1& is inconsistent.
There is a discrepancy between the rebate income for the condition
record and the sum of the rebate incomes at the levels tax codes/plants
(depending on the settlement type).
The income for the condition record amounts to &V3& in the rebate
arrangement currency. The sum of the incomes for the tax codes/plants is
&V4&.
The problem may be due to one of the following reasons:
Incorrect changes to the settlement structures in a user exit.
Error in the distribution program in the system for distributing incomes
among the tax codes or plants.

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

System Response

Settlement accounting has not been carried out for rebate arrangement
&V1& to avoid possible settlement errors.

How to fix this error?

Since this is a program error, contact your system administrator.

Procedure for System Administrators

If you are sure that this does not relate to a user exit error, contact
SAP, providing details of the circumstances that led to the error.
The condition record has (internal) number &V2&.

Error message extract from SAP system. Copyright SAP SE.