I never had this Time Machine problem before, only after upgrading to Sonoma. I do not use iCloud, Dropbox, OneDrive, Google Drive or any other Cloud services. I rebuilt Mac Mail accounts, tried turning off WiFi, using safe mode, and every troubleshooting trick I can think of. I wish I knew which process or daemon or PID was causing this so I could kill it in Activity Monitor. Apple online support is useless. Nothing on my MacBook is set to sync! "Some of the files on your Mac cannot be backed up until Cloud Files syncing has completed." Is there a .plist file I can delete? I'm on an M1 MacBook Pro.

  • already tried that, didn't work.
    – GeminiMac
    Oct 20, 2023 at 15:09

1 Answer 1


I would disconnect from all networks and restart your Mac and connect only the backup destination (if it's reachable via network, you will need to ensure that network has no way to get to the internet in general and Apple iCloud servers in specific).

Then run a backup to make sure everything is clear. Once that backup is complete you can reconnect to the internet and let iCloud sync resume and block backups until the sync down is done.

Here is a very good writeup of the issue - for most people it will be a large sync and some people will need Apple support if they can't triage this or wait it out.

It seems in fixing a "bug" some people have been depending on the buggy behavior to juggle which iCloud items are "optimized" and which need to be downloaded and present on the local storage. It's also possible Apple changes things server side or issues a patch to avoid sync deadlocks for days and prevent backups.

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