SAP Message 64461 - Position date: Period-end closing already executed after &1

Diagnosis
Position date &V1& is not permitted.
A period-end closing was already executed on or after &V1&.

System Response
No postings can be made using this function if the position date isbefore a period-end closing.

Procedure
Change the position date or reverse all flows posted in reverse orderup to the required position date.