Mac not unlocking after watchOS 7 update

My upgrade to watchOS7 took some time on my Series 3. After the update I had to remind my Mac that the watch could unlock it. My problems came after upgrading my Mac to Big Sur. Now my watch cannot- will not unlock my Mac.

The only thing that ever works for me is to unpair, then pair my Apple Watch again. Annoying because you have to re-add all your Apple Pay cards (well that is easy, but activating for one requires a call to bank which is the annoying bit) - but it does reliably allow me to set my Watch to unlock my Mac again. Had to do this twice - once when I got a new watch, and again when I upgraded to Big Sur.

SUCCESS! This may seem ironic, even counterintuitive, but I unpaired my Apple watch (series 6) from my iPhone, then re-paired them, then went in and then in the preferences Security and Privacy" successfully toggled "Use your Apple watch to unlock apps and your Mac," SUCCESS! Now the Apple Watch successfully unlocks my MacBook Pro! The Cloud had saved all my settings and re-pairing took a while but this worked.

SUCCESS! This may seem ironic, even counterintuitive, but I unpaired my Apple watch (series 6) from my iPhone, then re-paired them, then went in and then in the preferences Security and Privacy" successfully toggled "Use your Apple watch to unlock apps and your Mac," SUCCESS! Now the Apple Watch successfully unlocks my MacBook Pro! The Cloud had saved all my settings and re-pairing took a while but this worked.

I tried this several times and it did not work. However, SUCCESS! I unpaired my Apple watch (series 6) from my iPhone, then re-paired them, then went in and then in the preferences Security and Privacy" successfully toggled "Use your Apple watch to unlock apps and your Mac," SUCCESS! Now the Apple Watch successfully unlocks my MacBook Pro! The Cloud had saved all my settings and re-pairing took a while but this worked. I did have to re-enter Apple Pay security related data... but it's all good.

After upgrading all my Mac to Big Sur, auto unlock stopped working on my Mac mini (while still working on my MacBook Air and Pro). I tried Stoska992's procedure at least twice. Didn't fix.

Finally I decided to unpair/pair my watch (starting from the backup when pairing it). And it worked ! My watch now unlock all my Macs again.

Thank to you guys for sharing your experience here. Really helped me.

Yes when you unpair. But when you pair again your watch, you have the option to use the backup and when finished all your data and settings are back. really smooth and easy process.

The only thing I did is removing my cards from the wallet before unpairing and manually reinstall them at the end of the process.

Just to follow up. The stoska992 method noted as a solution in this thread worked for me--AW4 and Mac Pro (2013) running macOS Catalina 10.15.7 back in late September. However, a few days after updating to macOS Big Sur 11.01 last week, the unlocking first worked but stopped working again Monday. Yesterday, I simply signed out of iCloud, rebooted my Mac and signed back into iCloud per later suggestions in this thread but without again using the stoska992 method and unlocking started working again and still does today.

Yes I’m afraid only unpairing and re-pairing the watch worked for me. Deleting the keychain entries did not work. Can you put the watch to factory settings and then setup again from a backup? I’m guessing not...

This is all very strange and seemingly impossible to scope out. Neither my AW4 (OS7.1) nor AW0 (OS4.3.2) after a couple of days can again unlock my Mac Pro (2013) running Big Sur 11.01 with my iPhone 11 (iOS 14.2). However, both AW's still unlock my Mac mini (2014) running Big Sur 11.01 just fine.

First, the stoska992 procedure worked then just stopped working. Then signing out of iCloud, restarting and signing back into iCloud worked but now it has just stopped working again without any other changes. I'm sadly giving up on this broken feature....

Have you tried doing an NVRAM reset? First, if the feature is still enabled in System Preferences, try DISABLING it. Then, empty the contents of the ~/Library/Sharing/AutoUnlock folder. Then delete the Keychain Entries that you get when searching for AutoUnlock and Auto Unlock in Keychain Access (for any entries to show, enable ’Show Invisible Items’ in the View menu. Then, after deleting those entries, do the NVRAM reset. Then try enabling again. Note that enabling the feature for the first time nearly always fails because MacOS itself also has a tiny little bug in it; enabling it a second time should work. You may also want to unpair and re-pair your watch prior to the NVRAM reset, but it isn’t an absolute necessity, especially given the fact that your other system works with no problems.

In your case, be sure to only carry out this procedure on the Mac that is affected; leave the other Mac untouched.

Thanks csteelooper. I reset NVRAM (command-option PR at startup) but I did not do the stoska992 procedure again before resetting NVRAM. I'll give it a try and re-post. BTW, I've fixed the unlocking problem on my MacPro (2013) several times but it has just quit working after working for several days each time....

I know, this is definitely a frustrating issue. I’ve been having on-and-off results myself for quite some time, however, now it’s been working for almost 3 whole weeks running (*knock on wood*). For me, nothing fixed the problem until I tried Stoska992’s procedure with an NVRAM reset added in (you can find a post of mine outlining the exact order of steps a few pages back; I’ve summarised it for other peoples’ benefit. Also, it’s a pain that the update to Big Sur seems to have ‘reinstated’ the issue for some people… I just updated my fathers MacBook Pro (2015) to Big Sur and he had no problem with his AW2. But that may have been because it’s not on WatchOS7, as that isn’t supported on AW2. I’m anxious to see what comes from his AW6 when he’ll receive that later this year (Due for shipping by Dec 15).

Thanks again csteelooper but no joy. Curiously, I don't get the "Unable to communicate..." and the checkmarks actually stick in the Security & Privacy panel but still neither my AW4 nor AWO unlock my Mac Pro after putting it to sleep and waking. Maybe 11.1, now in beta, will fix this....

Way to go, glad that worked for you! I wish Apple would recognize a valid fix (work-around) like this and call it "Solved," 'cause the one labelled as such at the top of the string is a PITA and doesn't work!