Mac Data Recovery

Fix Time Machine Not Working after MacOS Update

Table of Content

    Summary: In this blog, we are going to talk about "Time Machine not working after updating macOS" problem. We'll provide feasible resolution along with discussing solutions for recovering lost data from Mac, iMac or MacBook systems.

    Apple’s built-in backup utility, Time Machine, is used to back up your Mac and all files stored on your HD. Backups are an excellent way to protect your data. However, you may encounter various issues with your Mac just after a macOS update. Today we will discuss Time Machine issues and what to do when Time Machine fails after the OS upgrade.

    How to Fix Time Machine not Working after Updating macOS?

    Here’s a quick checklist for repairing the Time Machine.

    A. Restart Your Mac

    The easiest solution to fix the issues is to restart your Mac. It deletes system-related stale data and fixes macOS’s odd glitches and bugs.

    Here’s how to do it:

    1. Go to the Apple logo and select Restart.

    Apple logo > Restart
    Apple logo > Restart

    2. When the Are you sure you want to restart your Mac message appears, uncheck the box next to Reopen windows when logging back in and click Restart.

    uncheck Reopen windows when logging back in
    Uncheck Reopen windows when logging back in

    3. After the reboot, reopen the Time Machine app and restart the backup process.

    B. Check the Latest macOS Updates

    One of the reasons you are having problems with Time Machine is that you have an outdated macOS version or installed it from a source other than the official Apple resources. 

    Follow the steps below to update macOS to the most recent version:

    1. Navigate to the Apple menu.

    2. Select About This Mac > Software Update.

    About This Mac > Software Update > Upgrade Now
    About This Mac > Software Update > Upgrade Now

    3. Search for new macOS updates in the newly opened window. If any are found, click Upgrade Now to get the most recent update.

    C. Try to Restart Time Machine Backup

    Stopping and restarting the backup process may help resolve the problem.

    To restart the Time Machine backup, perform the following steps:

    1. Select System Preferences from the Apple menu.

    Apple menu > System Preferences
    Apple menu > System Preferences

    2. Choose Time Machine.

    System Preferences > Time Machine
    System Preferences > Time Machine

    3. To cancel the current Time Machine backup, click the X button.

    4. Select Back Up Now.

    D. Run First Aid

    You can run disk diagnostics using the First Aid utility. It will help if the Time Machine issue is connected to the disk you use as a backup HD.

    You must first launch Disk Utility in Recovery Mode. Follow these steps:

    For Macs with Intel processors:

    1. Reboot your Mac.
    2. Hold down the Command + R keys.
    3. When the macOS utility window appears, launch Disk Utility.

    For M1-based Macs:

    1. Restart your Mac and hold the Power button until you see the Loading Startup Options message.
    2. Open the Disk Utility from the Gear icon menu.

    Do the following to run First Aid:

    1. Launch Disk Utility and select View > Show All Devices from the menu bar.

    Disk Utility > View > Show All Devices
    Disk Utility > View > Show All Devices

    2. Choose a disk > click the First Aid button > choose Run.

    E. Delete the Backup Disk

    The last alternative is to delete the Time Machine backup disk.

    To delete the disk, perform the following steps:

    1. Restart Disk Utility in Recovery Mode.
    2. Select the disk to be deleted.
    3. To complete the process, click Erase and follow the on-screen instructions.

    After that, you’ll need to restore your files. The most efficient solution is to use a specific restoring application, such as Stellar Data Recovery Professional for Mac, to restore the data that was saved on disk.

    Recover Lost Data Using Stellar Data Recovery Professional

    If you lost your data after the macOS update and issues with Time Machine, it is recommended to use Mac data recovery software to recover your deleted files. Professional data recovery software, such as Stellar Data Recovery Professional, can help you recover lost files on your Mac. It’s a helpful tool that can help you recover your files no matter when you lose them.

    To recover lost data, follow the steps below:

    1. Download the Stellar Data Recovery Professional for Mac software.

    2. After the installation, you will be prompted to select the data you wish to recover. 

    3. Select the needed files or click on Recover Everything.

    Stellar Data Recovery Professional > Select What To Recover
    Stellar Data Recovery Professional > Select What To Recover

    4. Then, decide where you want to recover the selected files from.

    Stellar Data Recovery > Recover From
    Stellar Data Recovery > Recover From

    5. After the Stellar Data Recovery scan, you will be able to see the files that can be recovered and choose which ones you require.

    Stellar Data Recovery > Preview
    Stellar Data Recovery > Preview

    6. Finally, select the destination folder on your Mac and begin the recovery process.

    Other Problems Connected with Time Machine after the macOS Update

    A. Problems with Terminal

    Sometimes after the macOS update disallows usage of Time Machine utility command from Terminal. For example, the following code throws an error message when executed from Terminal: $ sudo tmutil listbackups.

    After verifying the admin password, the OS throws the error: “The operation could not be completed because tmutil could not access private application data on the backup disk.”

    The message also suggests a resolution, “Use the Privacy tab in the Security and Privacy preference pane to add Terminal to the list of applications which can access Application Data.”

    The resolution is acceptable for a single-user environment but undermines security in the case of multiple user accounts. Even non-admin account holders have the same access privilege as the admin.

    In such a shared system, by using the data access rights, if any non-privileged account holder has accessed and deleted data like Mail, Time Machine backups, etc., then it can result in data loss.

    B. Problems with Snapshot

    Another issue faced by Mac users after the OS upgrade—Time Machine backs up data to the drive but fails to complete the snapshot, saying, “There was an error while copying files.

    The issue persists irrespective of the number of trials to back up the data. 

    To resolve this Time Machine backup issue, perform the following steps:

    1. Go to Apple menu > System Preferences > Time Machine.
    2. Turn off Time Machine.
    3. Go to Macintosh HD > Library > Preferences folder.
    4. Delete
    5. Start Time Machine from System Preferences.
    6. Add the external drive as a Time Machine backup destination.
    7. Create a backup to the drive.

    The newly created backup file is now accessible. 

    Wrapping Up

    Most of the issues related to Time Machine are simple to resolve. Unless you have a severe case of file corruption, going through some quick fixes in this guide should help you get Time Machine to back up your Mac properly again. Also, do not forget about the alternative of recovering files on a Mac by installing special restoring software like Stellar Data Recovery to ensure you can get all your files back.

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    About The Author

    Ruslana Lishchuk linkdin

    Ruslana is a tech content writer whose true passion is finding out about everything Mac-related. She specializes in creating macOS guides and tips & tricks. In her spare time, you’ll find her doing yoga or discovering local coffee shops in search of the best filter coffee.


    1. Hello, I need your help, after updating to macOS Catalina version 10.15.6 my Time Machine stays at Preparing backup… without actually proceeding any further (it stays in that status forever). I tried your #2 solution but that didn’t work. Any other ideas?

      1. Hi Mia, if the manual fixes didn’t work in your case then you should take it to the nearest services center. It may be possible of some other logical issues indeed, Thanks

    2. Hi! Thank you soooo much. All of a sudden none of my Time Machine back up disks could mount or be recognized in Mojave 10.14.6. Because I have 2 disks with the same problem, I could exclude connection issues. IThe back-ups worked 14 days ago. Additionally, other divisions on the disks would mount. I could not find a solution on the web anywhere, till I found you. It worked!!! Your help made me very happy! Stupid Apple updates…

    3. After upgrading to Mojave, I was having trouble completing Time Machine backups – would always give me an error message. After much troubleshooting, I stumbled across your page and Solution #2 worked for me! Thank you!!

    4. Hello Vishal,
      Solution #2 worked for me!!
      I had problem with TM Disable button (Back Up Automatically), when I click it, it fails to disable.
      I have previously removed all local snapshot and then removed the plist file.
      Nw I am able to disable TM.

    5. I tried solution #2, after many other solutions, it did not fix my issue.

      Time Machine stops at “Preparing backup”.

      This issue started after the OS upgrade to Mojave.

      1. Hello Larry,
        If the second solution is not working and there is data loss from the Time Machine backup drive, use Stellar Data Recovery Professional for Mac to recover your lost data.
        Free download, install and launch the demo version of the software to scan the Time Machine storage drive and preview the recoverable files. Thanks

    6. Connected the old Time Machine to my new iMac and stupidly formatted it making all files gone forever. How should I restore it back?

    7. Thank you so much!
      I have tried every hint, trick, and tip I could find to get Time Machine to back-up again after installing Mojave, and this is the only one that worked.

    8. Harold, Is your drive working fine after formatting? You can restore your lost backup files using Stellar Data Recovery Professional for Mac. Connect your Time Machine Drive to your Mac and run the software. Once you find the recoverable files, activate the software to save at required location.

    9. After upgrading Mojave I plugged in my external HDD that I use as a Time Machine. After plugging it in, it started writing data, but then failed in about the but then failed in about the same place every time. Giving message that there was an error copying files. I tried again, but no success. So I ran First Aid on the partition and it found nothing wrong. After doing many fixes, finally I formatted my Time Machine and lost all backup files. What should I do now?

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