Partner determination schema & for arrangement type & not defined

What causes this issue?

Partner schema &V1& for arrangement type &V2& is not defined.

System Response

The function you invoked cannot be performed.

How to fix this error?

Please look into the matter. The relevant rebate arrangement has the
number &V3&.
Either you must maintain partner schema &V1& or correct the assignment
to arrangement type &V2&.
INCLUDE 'NA_CUST_MAINTAIN' OBJECT DOKU ID TX LANGUAGE E
IF &DEVICE&='SCREEN'
Maintain partner schema &V1&.
<ds:TRAN.OMZ8>Perform function</>
Maintain the assignment to arrangement type &V2&.
<ds:TRAN.OMZ9>Perform function</>
ENDIF

Error message extract from SAP system. Copyright SAP SE.