My Time Machine backups were working fine until I updated to 15.0.1. Now I constantly get:
The NAS is working fine. I have restarted my Mac and restarted the NAS. Just stopped working after upgrade to 15.0.1.
Mac Studio (2023)
I wish I found this thread a two weeks ago, but I have some good news. After struggling with this for days, I contacted Apple. After days of back-and-forth calls with them, my third Advisor confirmed that in macOS 15.0.1 they introduced a bug in the Firewall feature, that they are working on a fix (hopefully a soon-to-be released 15.0.2), and there is no setting that we can make to create a firewall pinhole (which I asked for).
In the meantime the recommended work-around is to set Time Machine backups to be manual (not hourly or daily), to turn off the Firewall when ready to do a TM backup, manually kick it off, and (when it is done) to turn the Firewall back on. Effectively, we have to "lower shields to use the Transporter" (Trek fans will recognize the analogy). It sucks, but at least it gets the job (sort of) done.
I would recommend, before you run your next TM backup, you "lower shields" (Firewall) and option-click on the TM Menu Bar icon to run a Verify process to be sure that this problem hasn't corrupted your TM backup. After this happened (on October 3), my TM back up was corrupted and I had to start over (twice or three times during the debugging process).
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And it gets worse. I'm running 15.1.1 on M2 MacBook Air into a home-brew Ubuntu server with Samba and Time Machine settings. It's worked for a few years quite reliably. Now it stopped with 13% done claiming out of disk space (wrong because TM manages disk space through quota settings on the server). Before I read this thread, I did the usual fix of forgetting and attempting to reattach the TM share; failed big time because I can't modify the Registered User name and can't type more than one character of the password. I've tried the shields (firewall) down approach with no change.
Apple you've really messed up this time.
I have exactly the same error when backing up to my NAS since installing the 15.1.1 Update. Prior to that I've not had any issues with Time Machine backups. The NAS is working fine, and there were no other IT changes.
I've scoured the various forums for a solution but have not found anything that works. I've resorted to backing up my iMac to a USB external until Apple figures this out.
Yep- same for me. At least it works some of the time, so an improvement, but my mileage is that some TM backups work and some fail with "Some Files are in use/unavailable". Disappointing QA from Apple, but at least I've got *some* backups now on 15.2!
There is the perfect word in German to describe Apple's problem with MacOS 15.x and Time Machine on an Apple Airport Extreme: "Schlimmerbesserung" (which loosely translates to worsened improvement).
15.0.1 required me to completely wipe and restart my Time Machine from scratch.
15.1 no joy, several disconnections and "Time Machine full" warnings
15.2 worked (sort of) but started slowing down the entire machine (making it feel more like an Intel driven machine rather than an Apple Silicon driven machine)
15.3 has blown up to over 700% CPU, and essentially grinding the machine to a halt requiring a Force Quit on diskimageiod to get anything to work on the machine (multiple times through the day).
Is there a workaround or do I need to stop using Time Machine (this problem has now existed for over half a year with Apple not fixing the underlying problem of limiting CPU usage for Time Machine).
This option works for me too.
But it's happening since the update to MacOS 15.0.1. So Apple should fix this problem I think!
Unfortunately it does not. It fails at the end indicating that some files were not available! Disappointing QC with Apple.
This is an unbelieable bug that should not happen.
How come an udpate is not tested in such a configuration that is so common.
Something is not working at apple software quality assurance
Nope! Still not working.
I spoke too soon. After 15.2, backups *sometimes* work with the firewall enabled. They still fail about half the time, with "some files unavailable" or "backup disk disconnected during backup".
No. 15.2 did not fix it. And I do not force sleep or use a firewall on this machine.
Apple knows about it and better fix it as TM is mission critical.
After a few days it appears on my M4 that TM is somewhat sporadic. When it fails it is usually around 75% complete when it reports it cannot find disk.
Problem remains at 15.2.
Switching off firewall does not resolve the issue either.
Mine is not working on 15.1.1. I am not using the firewall.
Since update to MacOS 15.0.1 Time Machine backups do not work
