macOS Big Sur and watchOS 7 are exciting updates with lots of cool features. However, they bring their share of weird bugs and glitches that can be annoying. One of the issues I faced recently was that Apple Watch with watchOS 7 fails to enable auto unlock with macOS Big Sur. I was getting errors like “Unable to communicate with Apple Watch” and so on. If you’re in the same boat, don’t worry. Here’s how to fix Apple Watch that won’t unlock Mac with macOS Big Sur.

Fix Apple Watch not unlocking Mac with macOS Big Sur

Many users are facing these issues and unfortunately Apple has not officially acknowledged the bug. This means that we don’t have a single solution that we can recommend here. However, we have a bunch of things you can try. They worked for me so I’m sure they will fix the problem with your Apple Watch as well.

I’m adding links to each of the methods below so you can quickly jump to the one you want to try. That said, I’ll list these methods in ascending order of difficulty, so you can start at the top.

1. Check for software updates

The first thing to do for such issues is to make sure you have the latest software on your Mac and Apple Watch. Apple may not have publicly acknowledged the issue, but it’s likely to send out a fix soon. So, check for software updates and download the latest version available. Here’s how you can do it.

On your Mac

  • Go to System Preferences and click Software Update
  • It will automatically check for updates and notify you if any updates are available. While you’re here, also turn on “Automatically keep my Mac up to date” if you haven’t already.

On your Apple Watch

  • Go to settings on your watch
  • Tap General
  • Press on Software update
  • Install available updates, if any.

You can also use your iPhone to check for watchOS updates.

  • Open the Watch app on your iPhone, and tap General.
  • Tap Software Update to check for available updates for your Apple Watch.

Apple actually claimed that watchOS 7.1 fixes the issue of Apple Watch not unlocking Macs with macOS Big Sur. However, for many users, myself included, this didn’t seem to fix anything. However, it’s safe to assume that the company will release a proper fix in a future update.

If you are using watchOS 7.1 and things are not working for you, follow the next possible solutions.

2. Reset Bluetooth and Wi-Fi

A common error displayed by a Mac when trying to enable auto unlock with Apple Watch is “your Mac could not communicate with your Apple Watch”. This error is completely unnecessary and extremely irritating to see. However, resetting your wireless radios can help fix it.

On your Mac

Reset Wi-Fi

  • Click on the WiFi icon in the menu bar.
  • Disable your Wi-Fi.
  • Wait a few seconds, then re-enable WiFi.

Reset Bluetooth

    • Open Control Center from the menu bar. Click the Bluetooth icon to turn it off.
  • Wait a few seconds and re-enable Bluetooth.

On your Apple Watch

  • Swipe up on the watch face to open Control Center.
  • Tap the Airplane Mode icon to turn off all radios on your watch.
  • The icon will turn yellow. Wait a few seconds and then turn Airplane mode off.

Now try to enable Auto Unlock with Apple Watch.

3. Disable automatic login

You may not be familiar with this feature, but it exists and disabling it apparently helped solve the problem for some users.

  • Open System Preferences on your Mac and click Users & Groups.
  • Click Login Options
  • If automatic login is enabled, disable it.

4. Sign out of iCloud on Mac

macOS Big Sur has a lot of issues with things like Handoff and Sidecar. Most of them were solved by users signing out of iCloud on their Mac. It turns out that it also worked for a group of people facing the Apple Watch error we are facing today.

  • Go to System Preferences and click ‘Apple ID
  • Click Logout to sign out of your iCloud account on your Mac.
  • Restart your Mac, then sign in to iCloud again

By the way, this is the solution that finally worked for me, and I really hope it fixes the problem for you too. Because the other methods are either extremely time consuming or just too much work.

5. Reset Apple Watch

If none of the steps worked for you, you should try resetting your Apple Watch. This means you need to unpair your Apple Watch and then set it back up with your iPhone.

This is a time consuming process, so be patient. Or, if you prefer to consider this as a last resort, you can try the following method before this one. It’s your call.

6. Adjust the key fob

It’s probably less extreme than resetting your Apple Watch, but it’s also time consuming and you’ll have to play around with the keychain a lot. That’s why I put this as the last method on this list. If nothing has worked for you, however, here’s another thing you can try.

To note: I haven’t tried this particular method. However, it was mentioned on a forum and a lot of users claimed that it solved the problem for them, so I’m including it here as a last resort for you guys.

  • On your Mac, search for “keychain access” in Spotlight, or an alternative Spotlight app like Alfred.
  • Click View in the menu bar and activate “Show invisible items”.
  • In the Keychain Access search bar, type ‘Automatic unlocking‘. A lot (and I mean parcel) items with the name ‘Auto Unlock’ will be displayed.
  • Select them all and delete them.
  • Now, to researchAutomatic unlocking‘ (without spaces this time)
  • You will see four items. Select them and delete them. If they reappear, don’t worry. Just go forward.
  • Now open Finder. Use keyboard shortcut command+shift+G to open ‘Go to Folder’ dialog. Move towards ” ~/Library/Share/AutoUnlock“. Remember to include the tilde symbol in the path.
  • Here you will see two files. ‘ltk.plist’ and ‘pairing-records.plist’. Delete these two files.
  • Restart your Mac.
  • Return to System Preferences and enable Auto Unlock with Apple Watch. You will need to activate it twice. The first time would have failed, but the second time should work.

Fixed: Apple Watch not unlocking Mac with macOS Big Sur

There are many Apple Watch issues in nature but this one is extremely annoying. Hope these solutions solved the problem you had. Personally, I was able to fix the problem by signing out of iCloud on my Mac, which is great because I didn’t have to worry about resetting my watch or tweaking the keychain. So which step worked for you? Share your experience in the comments so that other users can also find the easiest way to solve their problems.