Only reporting point backflushes allowed in current or previous period

What causes this issue?

You are attempting to enter reporting point backflushes or goods
receipt postings for a period which:
Is in the future
The system may interpret the current period as the future period, since
the <DS:GLOS.3526C024AFAB52B9E10000009B38F974>period closing program</>
has not yet been run.
Precedes the previous period
This is not possible.

System Response

The system does not perform the posting.

How to fix this error?

You cannot enter postings for a period that is earlier than the
previous period.
Check whether the period closing program has been run.
Enter the postings in the current period or in the previous period.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.