Please check account settings

What causes this issue?

A balance has been found during the creation of the credit memo (see
foregoing error message).
It is likely that the accounts for rebate income and provisions for
accrued rebate income have been set up wrongly.

System Response

Settlement accounting is not possible for this rebate arrangement.

How to fix this error?

Check the settings of the accounts for rebate income and provisions for
accrued income.
The parameter "Tax category" must be set to "-" (only input tax
allowed) for both accounts. The indicator "Posting without tax allowed"
must be set.
If necessary, contact the person responsible in this connection.

Error message extract from SAP system. Copyright SAP SE.