1854613 - Manual Payment Clearing - Posting Date Not Permitted - Posting Date Can't be Edited

After uploading bank statement X (X is the bank statement ID) a payment is allocated to supplier account XYZ (XYZ is the supplier account ID) containing the bank statement posting date DDMMYYYY. When trying to clear the payment against an invoice with a posting date DDMMYYYY-1, you receive the error: Posting date DDMMYYYY not permitted. The item to be cleared already has postings assigned to it with posting date DDMMYYYY +1. Enter a posting date equal to or after DDMMYYYY +1.
When trying to adjust the posting date of the manual clearing you notice that the field Posting Date is not editable.

For example:

An uploaded bank statement has the posting date 13.02.2013. Both payment allocation and payment clearing in status In preparation have the posting date 13.02.0213. In the manual payment clearing an invoice with the posting date 01.02.0213 shall be cleared. You receive the error: Posting date 13.02.2013 not permitted. The item to be cleared already has postings assigned to it with posting date 25.02.2013. Enter a posting date equal to or after 25.02.2013.

SAP Business ByDesign

payment allocation. Zahlungszuordnung; "Buchungsdatum nicht zulässig. Dem auszugleichenden Posten sind bereits Buchungen mit dem Buchungsdatum und Belegnr. (Ausgleich) zugeordnet. Geben Sie ein Buchungsdatum ein, das am oder danach liegt."; Manual Payment Clearing; Posting Date Not Permitted; Posting Date Can't be Edited; , KBA , SRD-FIN-ACP , Payables , How To