Diagnosis
You have made a retroactive change to an advance payment.

System Response
The system will therefore also create corresponding credits if asettlement has already been carried out for the affected rental unit inthe specified period.

Procedure
If you really want to carry out the change, make sure that nosettlements have been carried out for the corresponding rental unit inthe affected period.
If not, enter a future date as the start date for the validity periodof the condition.