Time machine backup not completed Message

For the past few months I am having problems with my external drive I use for Time Machine. I will click on TimeMachine and select backup now. I generally leave my Mac alone and when I come back I receive the following messages. Time Machine couldn't back up to "Time Machine MacBook Pro". I then click on that message and get "An error occurred while preparing the backup."


The backup disk is an external sandisk passport the I've use repeatedly. I have deleted old files and am at a loss. The disk has a USB that I plug into an Anker adapter. I've been having this problem for a few months, but usually after 2 or 3 tries it completes the back up.

MacBook Pro 16″, macOS 12.1

Posted on Jan 16, 2022 3:20 PM

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Posted on Jan 16, 2022 3:31 PM

"An error occurred while preparing the backup."


^--that generally means a problem on the SOURCE drive. Have you used Disk Utility to check the boot drive, or restarted in Safe Mode (which does a Disk repair as it starts up) ??

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Jan 16, 2022 3:31 PM in response to DRR84

"An error occurred while preparing the backup."


^--that generally means a problem on the SOURCE drive. Have you used Disk Utility to check the boot drive, or restarted in Safe Mode (which does a Disk repair as it starts up) ??

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Jan 22, 2022 12:59 PM in response to DRR84

<< Do I run First Aid on the drive (Macintosh HD)? >>


that display shows several different items with VERY similar names. the one you have currently selected is the APFS Volume Group, and the data drive itself. You can do First Aid on anything you can select, and no damage will be done.


But the more important one is further down in that hierarchy.

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Feb 3, 2022 7:26 AM in response to Grant Bennet-Alder

I believe I found the problem. A few months ago my WD external drive fell off the desk and became detached from the base. I reattached, but the problem with backups started shortly after that. I bought a new external drive and backups are being done. Thank you for the help.

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Time machine backup not completed Message

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