SAP Message >0260 - Enter an alternative posting date (&1, &2, &3)

Diagnosis
The system has found that, during summary data transfer forreconciliation key &V1& and company code &2&, there are no open postingperiods for the posting date &V3&.
Posting is not possible.

System Response
Summary data was not updated.

Procedure
Either open the posting period again or specify a posting date in thealternative posting date field in which period summary data canbe posted.