Time Machine backup failure due to unavailable files on Mac

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Level 1

6 points

Time Machine backup failure due to unavailable files on Mac

I cannot figure out why I'm seeing this message. Time Machine has been working flawlessly for years. This started occurring a few MacOS updates a while back (Going to 15). My machine is up to date with the latest OS version. I back up to a OWC Thunderbolt enclosure with SSD for storage and spinning hard drive for Time Machine backups (2 drives in 1 enclosure). Once I get the error I can go on that drive in Time Machine and right click and click on the pop-up "Back Up to Time Machine now" and the backup completes successfully. It happens when I am not using the computer overnight. The machine is not set to go to sleep - only to turn the monitor off after some time. It's almost like when machine goes unused for a while certain files "lock" and this might be preventing the backup. I don't know, I just suspect something like this might be happening.

[Re-Titled by Moderator]

Mac mini, macOS 15.2

Posted on Dec 21, 2024 11:12 AM

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Answer 1

Top-ranking reply

Juan Cabanela

Level 1

38 points

Jan 26, 2025 9:37 AM in response to Alan N

This is going to sound crazy, but do you have the FindMy widget running? I had this problem begin around the time I upgraded to macOS 15.2 and it was driving me crazy. The failure didn't occur unless the screen was locked, but it was inevitable if the screen was locked. I had tried to internet search my way to a solution a few times. I finally found it in this recent (Nov. 2024) post on MacRumors (https://forums.macrumors.com/threads/time-machine-error.2437741/ ) where the user checked the logs and discovers it is FindMy.

Assuming it is shortly after you have received this error message

Time Machine did not finish backing up because some files were unavailable. Backups will resume when your Mac is unlocked.

This is how you can check if FindMy is suspect on your machine:

Open the Terminal (in the Finder, go to Go > Utilities and then open Terminal or just Spotlight this)
Enter the following command exactly:

log show --info --style compact --predicate '(subsystem == "com.apple.TimeMachine")' --last 24h | grep "Operation not permitted"

This command searches the logs for the last 24 hours and sees if anything associated with TimeMachine triggered an "Operation not permitted" error. Lo and behold I had several lines of the same error (other than date stamps)

2025-01-25 12:38:29.847 E backupd[586:423f16d] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/DRIVENAME/2025-01-25-121611/Data/Users/USERNAME/Library/Containers/com.apple.findmy.FindMyWidgetItems/Data/SystemData/com.apple.chrono/snapshots/com.apple.findmy.FindMyWidgetItems/systemSmall--4438004920846669853----164.00w--164.00h--20.00r--0f--0.00t-0.00l-0.00b0.00t.chrono-timeline' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

So it appears the FindMy widget creates some sort of temporary files that TimeMachine is not being allowed access to, causing the failure. I had to turn off the FindMy widget and reboot (just turning off the widget didn't appear to release the file lock)... but my Time Machine is now working fine with the screen locked!

Maybe other apps can cause these problems, so this command might at least give us an idea of which file is causing the "Operation not permitted" with Time Machine.

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Answer 2

Old Toad

Level 10

217,546 points

Jan 26, 2025 1:43 PM in response to Alan N

Give this a try: boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

NOTE 1: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following;

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts

• Deletes font caches, kernel cache, and other system cache files

NOTE 2: if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode. This makes it act as a wired keyboard as will insure a successful boot into Safe Mode.

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Answer 3

iwaddo

Level 1

126 points

Feb 23, 2025 2:10 AM in response to Alan N

I started having this issue a few weeks ago, I even took the opportunity to buy a new disc, but the problem started again, very occasionally when the Mac was asleep.

The workaround is to delete the local Time Machine snapshots with this script in Terminal. This is not a fix as the problem returns after an unspecified period of time but it does allow the back up work when the Mac is asleep.

for d in $(tmutil listlocalsnapshotdates | grep "-"); do sudo tmutil deletelocalsnapshots $d; done

I plan to raise it with Apple and will let you know if I find anything useful.

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Answer 4

leroydouglas

Level 10

203,898 points

Dec 22, 2024 11:56 AM in response to Alan N

Alan N wrote:

I cannot figure out why I'm seeing this message. Time Machine has been working flawlessly for years. This started occurring a few MacOS updates a while back (Going to 15). My machine is up to date with the latest OS version. I back up to a OWC Thunderbolt enclosure with SSD for storage and spinning hard drive for Time Machine backups (2 drives in 1 enclosure). Once I get the error I can go on that drive in Time Machine and right click and click on the pop-up "Back Up to Time Machine now" and the backup completes successfully. It happens when I am not using the computer overnight. The machine is not set to go to sleep - only to turn the monitor off after some time. It's almost like when machine goes unused for a while certain files "lock" and this might be preventing the backup. I don't know, I just suspect something like this might be happening.

[Re-Titled by Moderator]

ref: Time Machine troubleshooting on Mac

Time Machine troubleshooting on Mac - Apple Support

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Answer 5

Alan N Author

Level 1

6 points

Dec 22, 2024 1:55 PM in response to AlWeir

I looked at these but none of these are the issue. Backups DO COMPLETE SUCCESSFULLY - But only after I right click on the volume in Time Machine settings and choose "backup Time Machine now". I get NO errors here. The error occurs when the machine is idle (i.e. overnight) and backups used to happen with no issue. Now they fail because a file is not available. It never tells me WHAT file(s). If I manually initiate the backup, everything is fine.

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Answer 6

Alan N Author

Level 1

6 points

Jan 26, 2025 1:31 PM in response to Juan Cabanela

I ran the grep but I think I manually backed it up the last few days. I chaged it to 96 hours and nothing found. I am going to not run any manual updates and wait until I see the error and run the grep again. I will report my findings.

I APPRECIATE the information - this actually makes good sense.

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Answer 7

Alan N Author

Level 1

6 points

Jan 27, 2025 3:28 PM in response to Alan N

I had the Time Machine error today. I initially thought it was the find my since I had an error show after the grep search. However under closer examination, it doesn't appear to be Find My, but some other disk issue. Here is what I see:

2025-01-27 16:08:30.471 E backupd[537:d4e37f] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/

2025-01-27-160412/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-01-27 16:37:58.478 E backupd[537:d55b4d] [com.apple.TimeMachine:FileProtection] Failed to proactively acquire device lock assertion on lock state change (deviceIsLocked), assertion state: <dropped>, error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-01-27 16:39:15.378 E backupd[537:d55b4a] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/

2025-01-27-163658/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-01-27 17:48:18.950 E backupd[537:d64c02] [com.apple.TimeMachine:FileProtection] Failed to proactively acquire device lock assertion on lock state change (deviceIsLocked), assertion state: <dropped>, error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-01-27 17:49:41.826 E backupd[537:d646a5] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/

2025-01-27-174651/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

I'm wondering if something might be corrupted with the Time Machine disk itself? I have several external drives that are on the system and get included in the Time Machine image, but I don't see any of these referenced.

I'm thinking maybe stop the time machine process, reformat that HDD and have it start a new time machine.

Thoughts anyone??

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Answer 8

AlWeir

Level 5

5,363 points

Dec 22, 2024 11:32 AM in response to Alan N

Here is a whole lots of reasons why Time Machine fails at Backups and possible solutions

Fix Time Machine Couldn't Complete the Backup

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Answer 9

Alan N Author

Level 1

6 points

Jan 27, 2025 3:16 PM in response to Juan Cabanela

.

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Answer 10

Feb 11, 2025 7:14 AM in response to Alan N

I’m getting this multiple times a day. My month old M4 Mac Mini is backing up with Time Machine to three different disks: 1 x Drobo NAS, 1 x Drobo DAS and 1 x Toshiba 2T HDD (reformatted yesterday).

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Answer 11

Alan N Author

Level 1

6 points

Feb 23, 2025 6:59 AM in response to iwaddo

Sounds exactly the same. I will run the command and see if this temporarily fixes the issue. Something changed recently in one of the later updates to invoke this.

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Answer 12

Alan N Author

Level 1

6 points

Feb 11, 2025 9:34 AM in response to Old Toad

I appreciate the response, but please re-read my post. Backup DOES WORK! It just does not work Automatically without throwing the error. I can then go in system settings and open the volume in the Time Machine section and right click and manually complete backup and it works. So backup is NOT BROKE - the process when the machine is idle and the screensaver is running causes the error. My keyboard is hard wired USB-C.

I can run a command in terminal and I can see the error in the logs, but the error does not point to any certain file or drive. Here is the output of running a command to look for the time machine logs:

Here is the text in case it is hard to read. It reflects a device locked, but I sure don't see where it reflects on WHAT device is locked!

Last login: Tue Feb 4 11:13:59 on console

apn@Alans-Mac-mini ~ % log show --info --style compact --predicate '(subsystem == "com.apple.TimeMachine")' --last 96h | grep "Operation not permitted"

2025-02-11 05:40:19.107 E backupd[262:57cc81] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/2025-02-11-053917/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 06:39:32.984 E backupd[262:583da3] [com.apple.TimeMachine:FileProtection] Failed to proactively acquire device lock assertion on lock state change (deviceIsLocked), assertion state: <dropped>, error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 06:40:24.610 E backupd[262:583da5] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/2025-02-11-063925/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 07:39:42.943 E backupd[262:58b15f] [com.apple.TimeMachine:FileProtection] Failed to proactively acquire device lock assertion on lock state change (deviceIsLocked), assertion state: <dropped>, error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 07:40:39.393 E backupd[262:58b114] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/2025-02-11-073933/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 08:40:11.333 E backupd[262:5925a7] [com.apple.TimeMachine:FileProtection] Failed to proactively acquire device lock assertion on lock state change (deviceIsLocked), assertion state: <dropped>, error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 08:41:07.770 E backupd[262:5925a4] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/2025-02-11-084001/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 09:40:58.662 E backupd[262:599985] [com.apple.TimeMachine:FileProtection] Failed to proactively acquire device lock assertion on lock state change (deviceIsLocked), assertion state: <dropped>, error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 09:41:57.918 E backupd[262:5998e5] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/2025-02-11-094047/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 10:41:02.761 E backupd[262:5a1491] [com.apple.TimeMachine:FileProtection] Failed to proactively acquire device lock assertion on lock state change (deviceIsLocked), assertion state: <dropped>, error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

2025-02-11 10:42:03.582 E backupd[262:5a1494] [com.apple.TimeMachine:FileProtection] Failed to acquire device lock assertion for '/Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/Alan’s Mac mini/2025-02-11-104051/Data/Users/apn/Library/Metadata/Assets/com.apple.MobileAsset.SpotlightResources.plist' (assertion state: <dropped>), error: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"

apn@Alans-Mac-mini ~ %

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