Apple Watch Unable to Unlock Mac after Upgrade

Apple Watch has a nice feature which allows users to unlock their Macs automatically when the watch is near the Mac. Many Apple Watch owners make use of this convenience and have come to expect their Macs to open as soon as they sit down to use their computer. However, after upgrading to the latest macOS, Big Sur, some Apple Watch users are having trouble unlocking their Mac with their watch.

See also: Big Sur Bricking Some MacBooks: Blank Screen after Upgrade

Once you’ve gotten used to the Auto Unlock feature, typing in your password every time seems like an annoying inconvenience. Not to mention, things not working like they’re supposed to can make a person rightfully peeved. In this article, we will go through some troubleshooting steps to help you get Auto Unlock working again with your Apple Watch.

See also: How to Downgrade from MacOS Big Sur to Catalina

First of all, we will go through the basic steps involved in setting up Auto Unlock, then we will lay out some suggested fixes. Note: If you have recently upgraded your computer – like within the last day – you may want to wait and see if your Mac simply needs a little time to complete the upgrade process.

See also:

Remember: After you turn on, restart or log out on your Mac, you will need to log in once manually with your password. Auto Unlock will open your Mac after that.

See also: How to Change the Login Screen Background in macOS Big Sur

How to Set Up Auto Unlock

We assume in this article that, because you’ve used Auto Unlock before, your equipment meets the requirements for Auto Unlock.

  1. Make sure that your Mac has the following settings in place:
    • Wi-Fi and Bluetooth are turned on.
    • Your Mac is signed in to iCloud and your Apple ID uses 2FA.
  2. Make sure your Apple Watch has the following settings in place:
    • Your watch is signed in to iCloud using the same Apple ID as your Mac.
    • Your watch uses a passcode.
  3. On your Mac, go to Apple Menu  > System Preferences. Choose Security & Privacy. Select the checkbox next to “Use your Apple Watch to unlock apps and your Mac.”
enable Auto Unlock


Update Apple Watch and Mac

Make sure you’re running the latest versions of watchOS and macOS. To check for updates:

  • Mac: Go to System Preferences > Software Update.
  • Apple Watch: Either check for updates on your watch, or on your iPhone.
    • On Apple Watch: Go to Settings > General > Software Update.
    • On iPhone: Go to Watch app > General > Software Update.

See also: How to Fix Apple Watch Battery Problems after watchOS 7 Update

Turn Auto Unlock Off / Back On

  1. Turn off Auto Unlock: Under System Preferences > Security & Privacy, deselect “Use your Apple Watch to unlock apps and your Mac.”
  2. Restart your Mac: Go to Apple Menu  > Restart.
  3. Turn Auto Unlock back on.

Reboot Mac and Apple Watch

Restart Mac

Go to Apple menu  > Restart.

Restart Apple Watch

  1. Press and hold the side button. Drag the Power Off slider.
  2. Power on your watch by pressing and holding the side button.

Additional Troubleshooting Ideas

The following are suggested fixes which have worked for some users. As always, when you will be making changes such as reseting devices or deleting files, first make a backup of your device(s). Only follow these suggestions if you are comfortable performing all of the steps required.

Reset Apple Watch

Most of your data on your Apple Watch can be restored when you re-pair. Your watch’s backup will not include your Apple Pay cards or your Bluetooth pairing info, so you will have to re-enter those.

  1. On your iPhone, open the Watch app. Make sure your watch is near your phone.
  2. Select General > Reset. Choose Erase Apple Watch Content and Settings. Tap to confirm, when prompted. If you are using cell service on your watch, choose to keep your plan.
  3. When you pair your watch again with your iPhone, select to Restore from Backup.

See also: How To Reset Apple Watch Password When You Forgot

Delete Keychain Auto Unlock Files

  1. Open Keychain Access: Open a Finder window. From the menu at the top of your screen select Go, then Utilities. Find Keychain Access in the Finder window. Double click to open.
  2. Go to the menu bar at the top and select View. Click to Show Invisible Items.
  3. In the search field, type Auto Unlock.
Auto Unlock entries in keychain
  1. Select all of the entries in the list that begin with “Auto Unlock: … ” (where the “…” is one of your Apple devices) and delete them.
  2. Search for “AutoUnlock” and delete files that appear in the list. Four files with Kind: talk, talk-nonsync, classA and classC.
  3. Open the Library folder: With a finder window open, select Go from the top menu. Hold down the Option key and select Library.
  4. Find the Folder Sharing/AutoUnlock. There should be two files inside named “ltk.plist” and “pairing-records.plist”. Delete these.
Auto Unlock files in library folder
  1. Go to System Preferences > Security & Privacy. Check to enable “Use your Apple Watch to unlock apps and your Mac.” If this fails, try again to check the box to enable.
  2. Some users have found that this did not work right away for them, however, when trying to enable Auto Unlock (step 8) hours later, they were able to get it working.

See also: How To Remove A Device From Your Apple ID Device List

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Dr. Stacey Butler is a tech writer at macReports covering news, how-tos, and user guides. She is a longtime Mac and iPhone user and holds a Ph.D. from the University of Illinois at Champaign-Urbana. Here is her LinkedIn profile.

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2 thoughts on “Apple Watch Unable to Unlock Mac after Upgrade”

  1. I have the new M1 MAC and found disabling TouchID fixed the problem for me. I don’t know why apple do this. They are over complicating MAC OS more and more! If the MAC has multiple ways to unlock then let the consumer do that! Why restrict people from being able to unlock their MAC’s. Very frustrating!

  2. The fix for WatchOS is in fact much simpler than documented here. No need to trick keychain entries etc. Simply: just ensure that the iPhone paired with your watch is unlocked when you reactivate the Auto Unlock with Watch feature in macOS.


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