Deviating partner schema for SDoc type &1 and SDoc type &2 for cancell.

What causes this issue?

The settlement document type &V1& and the settlement document type &V2&
for cancellation have different partner schemas.

System Response

This can lead to you being unable to cancel documents for the settlement
document type &V1& because the existence of the same partner roles in
the partner schemas of the involved settlement document types is checked
at runtime.

How to fix this error?

Edit the partner schemas of settlement document types so that the same
partner roles are defined in both schemas.

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.