Level 1

101 points

Your Mac was unable to communicate with your Apple Watch.

When I installed WatchOS 7 on my Series 4, I had terrible problems with the battery life. Usually when I put my watch on the charger at night, I would have about 50% battery left. After the update, my watch would last maybe 8-10 hours and then I'd start getting the 10% battery warnings. One of the solutions I found online was to unpair my watch from my iPhone and then pair it again. Doing this appears to have fixed the battery drain problem, but now I can not turn on the option to unlock my MacBook Pro with my watch.

To enable unlock with my watch I go to System Preferences -> Security & Privacy and tick the "Use your Apple Watch to unlock apps and your Mac." Sometimes I get prompted for my password to unlock my disk and sometimes I don't. In either case, "Turning on..." with a spinning icon is displayed for a few seconds, and then I get an error message from the subject of this post. It also says to "Make sure your Apple Watch is unlocked and on wrist, and your iPhone is unlocked."

This was working before I unpaired and re-paired my watch. I have tried all of the suggestions that searching for this error message brings up, including restarting everything, making sure everything is on the same WiFi network, disabling/enabling handoff, restarting bluetooth, disabling/enabling auto-unlock of watch from phone, logging my MacBook out of iCloud and back in again, etc. Nothing seems to help me get this option enabled again.

I would really like to get this option turned back on again. Any other suggestions?

MacBook Pro 15″, macOS 10.15

Posted on Sep 21, 2020 6:59 AM

Top-ranking reply

mark__t

Level 1

46 points

Posted on Sep 25, 2020 9:07 PM

This isn’t my solution but was posted in another thread by stoska992, but it worked for me!

I've finally fixed it! I found a bunch of errors related to "AutoUnlock" in the Console that was hinting to me that there was some invalid state on my Mac with keys and plists not being reset properly.

Steps (follow at your own discretion)

Open "Keychain Access"
In "View", enable "Show Invisible Items"
Search for "Auto Unlock"
You should see a whole bunch of application passwords for "Auto Unlock: XXXX's ..."
Select all records and delete (this will reset/disable auto unlock on other Macs if you use multiple Macs)
Whilst still in "Keychain Access", search for "AutoUnlock" (no space)
There should be 4 entries for "tlk" "tlk-nonsync" "classA" "classC"
Select 4 records and delete (don't worry if they re-appear, the system repairs this automatically)
Open "Finder" and navigate to "~/Library/Sharing/AutoUnlock"
There should be two files "ltk.plist" and "pairing-records.plist"
Delete both files
Open "System Preferences" and try enabling auto unlock. You may need to enable it twice, the first attempt will fail.

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Similar questions

384 replies

Sep 25, 2020 7:30 AM in response to TiggerGTO

Same here; after unpairing and pairing a Series 4 Watch due to poor battery life after WatchOs 7 upgrade I cannot use the watch to unlock my MacBook - "Your Mac was unable to communicate with your Apple Watch."

Sep 25, 2020 3:22 PM in response to TiggerGTO

I have exactly the same issue with Watch os7 and Mac 10.15.7 after updates and then re-pairing watch and iPhone (because of battery drain).

called Apple support who said “it is with engineering now”!

would welcome any more advice....

Sep 25, 2020 4:36 PM in response to duZ3N

I messed around with this for HOURS, even going thru the debug menu in Bluetooth. What finally worked for me was to do all of the steps above with the Keychain Access, THEN running the following Terminal script to clear the Bluetooth settings, as the clear/reset menu options in the Bluetooth menu don't ACTUALLY clear or reset anything <massive eyeroll>:

sudo rm /Library/Preferences/com.apple.Bluetooth.plist && sudo shutdown -r now

Sep 28, 2020 11:03 AM in response to mark__t

This method is the only one that worked of the many I have tried. I noticed that there were quite a few duplicates of "tlk" "tlk-nonsync" "classA" and "classC", so perhaps that was the issue. Thanks!

Sep 28, 2020 8:49 PM in response to mark__t

This solution worked for me. I tried lots of other suggestions found on the web, to no avail.

On Series 4.

Same issue, unpaired/re-paired to fix battery drain issue in watchOS 7. Fixed battery drain to some extent, but could no longer unlock either of my Macs with watch (one on Mojave, the other on Catalina).

Thanks for the solution!

Sep 29, 2020 11:17 AM in response to duZ3N

This solution did it. It took two attempts but the second stuck. Weird.

This happened after the iOS 14 update which killed the battery resilience of my AppleWatch. A un- then re-pair of the watch fixed that, but broke the unlock with applewatch functionality. Your fix did the trick.

Thanks for sharing.

TiggerGTO Author

Level 1

101 points

Sep 30, 2020 5:52 AM in response to bsolberg

@bsolberg, during the several weeks where this feature was broken for me, I tried this solution 2 or 3 times. Not only did it not work, but it caused me to have to add my credit cards back to ApplePay on my phone and my watch. I'm glad it worked for you though.

Sep 30, 2020 7:33 PM in response to hakarlmedskyr

Likewise!! Extremely disappointed with Apple. I have tried Literary EVERY option, trick, tips and so called solutions for My Mac not communicating with my Apple Watch. All requirements met, Connected perfectly the first day of my new Macbook set up and Disconnected a day later! I've tried all updates as well. Nothing!

I have been having the worst experience with multiple apple devices lately with NO RESOLUTIONS! This Is Unacceptable!

kerrh100

Level 1

4 points

Oct 1, 2020 1:50 AM in response to TiggerGTO

Hi Tigger

I am having the identical problem re battery whereby my series 5 would drain within 6 hours after a full charge, I spoke with support and after many different attempts to resolve I was told also to unpair and pair again, however, since turning all the functions back on i.e. always on and hand wash I still only get around 10 hours.

The inability to now not being able to open the mac with my watch is driving me nuts! I will keep an eye on your post to see if any solutions come forward, I am reluctant to reset the watch again so maybe hold out until Mac OS is updated.

kerrh100

Level 1

4 points

Oct 1, 2020 6:40 AM in response to TiggerGTO

Hey thanks for reaching out, I wish that I could say it did but unfortunately not, I followed the guidance to the letter and tried a few restarts without success.

i then tried deleting the files once again (as you noted they had replicated again) and restarted and nothing, although it did speed up the response of displaying the error message!

I further tried some of the other solutions in other threads with switching off hand off and back on but nothing

driving me nuts as I use my mbp a lot and it worked a treat before IOS14 and unpairing my series 5

thanks again

TiggerGTO Author

Level 1

101 points

Oct 1, 2020 6:45 AM in response to kerrh100

Well, like I said in a previous post, I keep trying to contact Apple to provide an update to this case since the senior support advisor walked me through taking and submitting logs. It seems to me like a support engineer armed with the logs and the solution that fixed it for me should be able to determine the cause of the problem and create a fix for it in macOS.

Oct 1, 2020 7:02 AM in response to kerrh100

My headache came when I bought my new Apple Watch SE. Wiped my old watch and traded it in. Got the new one, which works great BTW, a huge upgrade. But no more functionality for Auto Unlock on either of my Macs, which both worked fine with the old watch. I've tried all of the listed steps, but don't see a library entry (~/Library/Sharing/AutoUnlock) on either Mac. One's a MBP 2013 the other a MBA 2020. 🤔

kerrh100

Level 1

4 points

Oct 1, 2020 7:09 AM in response to TiggerGTO

Absolutely I think that is my next best step, thank you for posting all you have it seems a few have managed to get it to work.

ironic that we pay all this money and then find ourselves trying to resolve software issues!

take care

TiggerGTO Author

Level 1

101 points

Oct 2, 2020 7:22 AM in response to TiggerGTO

I finally had another call with Apple Service last night. I didn’t talk with the same senior advisor as before, but she seemed very pleased that I followed up to provide a solution to this problem. She also said that she has been seeing this issue lately. Hopefully the combination of the logs I uploaded and the solution provided in this thread will allow Apple engineering to fix this problem in macOS.

Jon P.

Level 1

26 points

Oct 5, 2020 12:43 PM in response to TiggerGTO

Just to add a voice to the mix. I was following apple advice to fix issues with activity routes not showing up after ios14 and iwatch 7.0.1 upgrades. Apples fix involved unpair and reinstall from icloud. Once this as done, I have been unable to use apple watch to unlock my mac. I tried the fix above and this did not work.

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Your Mac was unable to communicate with your Apple Watch.