SAP Message F5669 - Posting date is initial

Diagnosis
Fiscal year and period are derived from the posting date. The postingdate, however, is at the initial setting.

System Response
Fiscal year and period cannot be derived.

Procedure
A system error has occurred. The posting date transferred must have alegitimate value.

3739759KE0: Error message F5669
51953MR08: Enter posting date when reversing