Last automatic weekly backup completed 4 November. I noted that the log says:
Backup DB: 1 (schedule: weekly)
0000.008 (0) Processed schedules. Tasks now: Backup files: Backup DB:
0000.010 (0) Decremented the semaphore (fd) by 1
0000.011 (0) Semaphore (fd) still locked
0000.012 (0) No email will be sent - this backup set was empty.
0000.013 (0) The backup apparently succeeded (with warnings) and is now complete.
I presume this means it could not backup the database.
I tried to run backup again, but the Backup now button does not respond.