Bug with Time Machine

[donawalt]

Not sure how long this has been going on, but after a little testing I have determined that on my MBP '18 and MacOS 10.13.6, set to do automatic backup to an external disk, if I click on the TM icon, and Select 'Open Time Machine Preferences', if it's not doing a backup it will say 'Next backup: when disk is connected', even though the drive is connected and accessible thru Finder, and if I do a 'Backup Now', it will start.

I can just ignore that message, and the next backup occurs an hour later as it should. Also, when examining 'Time Machine Preferences' if you uncheck 'Automatic backups' and immediately re-check it, the message changes to 'Next backup: <an hour from the last backup>'.

So the message is being erroneously displayed.

 

[ItWasNotMe]

On my system this message occurs quite often if you start preferences when he disk is connected but powered down. Its spurious in that in these circumstances resets when the disk next powers up.

Have you looked at the history in Finder to see whether you are actually having TM create the right number of backups?

 

[donawalt]

Have you looked at the history in Finder to see whether you are actually having TM create the right number of backups?

Yes, the history is perfect. There are no issues with how the TM is operating other than the message falsely reporting a disconnected drive! I can live with it now that I know it's a false message, maybe it's fixed in Mojave.

 

[ItWasNotMe]

Its not new in 10.13.6, but I can't remember how long its been doing this.

On my system, resets to proper message once drive has been spun up by TM.