"This session is more than 7 days old: only the school owner can still change its attendance."

Where: Finish, on the attendance sheet (instructor).

Why: an instructor can take or correct attendance on the day and during the following 7 days. After that, only the school owner can, with no date limit.

What to do: ask the school owner to enter or correct this attendance. If the session was waiting in the device's send queue, it becomes "Not sent": remove it once the owner knows.