Settlement acctg. already effected for reb. arrangement & (display only)

What causes this issue?

Settlement accounting has already been effected for rebate arrangement
&V1&. No changes in the data are therefore allowed.

System Response

The data can only be displayed.

How to fix this error?

If you nevertheless wish to change the rebate arrangement, you must
delete or cancel the already created documents. In particular, it is
possible to carry out a comparison and agreement of business volumes
again once the settlement documents have been cancelled.

Error message extract from SAP system. Copyright SAP SE.