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

eh48

Level 1

8 points

Oct 6, 2020 9:09 AM in response to mark__t

I have exactly the same issue after running first into battery problems and unpairing and re-pairing my watch. I went through this process of deleting everything, restarted my MacBook Pro running the latest OS10 update (10.15.7) and still get the "Your Mac was unable to communicate with your Apple Watch." message when trying to set up my series 4 watch. I guess I will just wait for a fix.

andy249

Level 1

4 points

Oct 8, 2020 7:17 AM in response to TiggerGTO

Thanks

I had a upgraded my S3 to new Watch SE, nothing worked, I was on call to Support for two hours trying different things, I even sent my watch back and had a replacement.

The solution posted by Mark worked for me.

WestW53

Level 1

23 points

Oct 8, 2020 4:35 PM in response to WestW53

Now unable to get either watch to Auto-Unlock my Macbook Pro despite constant reboots / restarts / deletion of keychain items and pref files.... Followed all options in this thread and still can't get it to work. Time to give up until Apple engineers find a fix. Extremely frustrating.

aagraw

Level 1

4 points

Oct 12, 2020 5:50 AM in response to aagraw

Now i am facing another weird issue. When I started the MAC later, after the MAC locks and i click and button, the screen appears saying "Unlocking with your apple watch" but then it right away asks for the password. It doesn't unlock now...this is sooo frustrating ...any one have any resolution to this?

MrQR

Level 1

4 points

Oct 13, 2020 2:20 AM in response to TiggerGTO

yay - this finally fixed my problem!!! Thankyou!! I tried all of the same suggestions (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 Mac out of iCloud and back in again, etc.) but this is what worked in the end!

26glenn

Level 1

8 points

Oct 16, 2020 7:29 AM in response to TiggerGTO

Unfortunately this did not work for me after multiple attempts. I think I'll wait for a proper software update from Apple. There must be thousand of users with the same problem and they seem to have had these difficulties over a number of years and Watch versions.

26glenn

Level 1

8 points

Oct 16, 2020 7:55 AM in response to 26glenn

I take back my remarks above. I left my MBP to do something else. When I returned I logged in as usual with a password, then miraculously a pop up appeared inviting me to turn on my Mac with Apple Watch.

Many thanks to mark__t and TiggerGTO and everyone else on this thread.

Oct 16, 2020 8:32 AM in response to 26glenn

Yea, once it works it should be good. I noticed that the previous times I tried it, my "Auto Unlock: Watch Name" never populated in my iCloud Keychain. But once I did this, it showed up. I think that's necessary for Auto Unlock to work for any Mac. So once you have it, you should be good to unlock any Mac :-).

Oct 16, 2020 11:38 AM in response to TiggerGTO

watchOS 7.0.2 re-broke my fixed unlock feature for my newly purchased watch series 6 ... now these procedures don't work to re-enable it ... "unable to communicate ... blah blah blah"

thank you iapple

nws75

Level 1

8 points

Oct 20, 2020 5:22 AM in response to danmitchell

This was my identical experience. I went beyond and reinstalled Mac OS X on both my MBP and iMac and the problem STILL has not been resolved. Not sure what else to do other than wipe my machines and do a clean install, which I am not willing to do.

Oct 21, 2020 12:02 PM in response to TiggerGTO

I used the 12-step solution provided by @mark__t and it worked quite well. The only slight change I made is that in step 9, I used the Terminal app to navigate to ~/Library/Sharing/AutoUnlock, and I first (quite unsuccessfully) tried the disable/enable keychain solution. Other than that, thank you @mark__t!

tjmars17

Level 1

4 points

Oct 21, 2020 8:01 PM in response to TiggerGTO

Any update on this issue? I'm having the same issue as well and tried everything above.

My setup is an Apple Watch 4 with Watch OS 7.0.2 and MacOS 10.15.7 on a Mid 2015 MBPwRD.

Thank you for any updated info.

Oct 23, 2020 8:35 AM in response to JDB1972

I had to do the fix a few weeks a go when I upgraded to watch os 7 on a series 3. Since then I've changed my series 3 to a new series 6 and it worked first time without having to do the fix again on the iMac

My partner who also changed from a series3 to a series 6 at the same time did have to re do the fix on the MacBook. Can't explain that!

The method originally posted by mark_t works perfectly though.

Oct 23, 2020 11:18 AM in response to TiggerGTO

Worked for me. The search for "Sharing/Unlock" worked but not the search for "~/Library..." as per Mark_T. Thank you very much TiggerGTO and Mark_T. Now only to wonder why this happened and if it will happen again. High hopes!

ianb11

Level 3

553 points

Oct 26, 2020 8:34 AM in response to apescapes

Tried everything on this thread including the toggle of the keychain & no luck.

Does Keychain have to be enabled on your iPhone as well as you Mac?

Keychain isn't something I've bothered with before.

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Your Mac was unable to communicate with your Apple Watch.