SAP Message 60689 - Start date & of old and new periods is not the same

Diagnosis
You tried to assign a new account settlement variant which has itsfirst account settlement period starting on a date different to that ofthe current account settlement period from the old account settlementvariant which is to be replaced.

System Response
The entry is refused.

Procedure
Enter an account settlement variant which has a first accountsettlement period starting on the same date as the current accountsettlement period of the old account settlement variant.