Your Mac was unable to communicate with your Apple Watch.

Question

Level 1

90 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

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Answer 1

Best reply

mark__t

Level 1

34 points

Sep 25, 2020 9:07 PM in response to TiggerGTO

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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Answer 2

duZ3N

Level 1

9 points

Sep 23, 2020 12:19 AM in response to TiggerGTO

After spending hours trying tons of various suggestions for exactly the same issue, this suggestion solved the issue.

https://discussions.apple.com/thread/251803595

What I did after following the above (just in case it mattered):

Toggle "KeyChain" off and then back in iCloud settings on the Mac.
Restart the MacBook.
Then, went to enable the "Use your apple Watch..." checkbox and after 1-2 attempts, it worked!

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Answer 3

bsolberg

Level 1

10 points

Sep 29, 2020 5:04 PM in response to bsolberg

I finally found a solution to my problem. It may be what triggers the list of actions mentioned earlier in this thread (which didn't work for me), but I

Logged out of my Apple ID profile on my iPhone
Logged out of my Apple ID on my MacBook
Logged back in my AppleID on my iPhone (merging iCloud backup)
Logged back in my AppleID on my MacBook
Rebooted my MacBook
Toggled the "unlock with Apple Watch", failed
Toggled the "unlock with Apple Watch" again, success!

Voila!

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Answer 4

Nov 22, 2020 4:31 AM in response to TiggerGTO

I had the same issue with Apple Watch 6 (watchOS 7.1) and MacBook Pro 13 early 2015 (Big Sur). So I repaired it with some steps:

1) I disabled Keychain synchronisation on MacBook (Settings/iCloud/Keychain)

2) I made steps in this thread https://discussions.apple.com/thread/251803595?answerId=253458029022#253458029022

- 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

3) Disconnected Watch from iPhone

4) Connected back Watch to iPhone (set it from backup)

5) Restarted MacBook

6) Turned on Keychain in iCloud settings

7) Enabled Auto Unlock for Watch in System Prefs

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Answer 5

Jul 1, 2021 9:08 AM in response to TiggerGTO

Here is my variation on this thread.

After using the suggestion on here - https://discussions.apple.com/thread/251803595, I did the following:

Toggle "KeyChain" off
Shutdown my iMac
Power Up the iMac
Toggle "KeyChain" on, wait until it is checked
Your AppleWatch will prompt you to log into your iCloud account. If you have it saved, you can scroll through it and select it. Otherwise, you will need to type it into the tiny AppleWatch window
Go to System Preferences and enable the "Use Your Apple Watch..." and enter in your Mac login password. it should work. It may take a while for the two devices to communicate

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Answer 6

TiggerGTO Author

Level 1

90 points

Sep 24, 2020 3:12 PM in response to Nitin_Kaushik

I ended up having 3 or 4 chat sessions with support, and eventually got my case escalated to a senior service advisor. We have tried everything including reinstalling macOS. None of it fixed the problem. He had me download a tracing/logging tool and I recreated the problem. I uploaded about 500MB of logs and a screenshot of the error message. He’s escalating the problem to engineering.

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Answer 7

TiggerGTO Author

Level 1

90 points

Sep 25, 2020 7:18 AM in response to TiggerGTO

Well, it sounds like there’s at least a few of us with the problem. Like I said, I have pursued it far enough to get a senior support engineer works with me over the phone and get the issue escalated to engineering. When/if I get a resolution, I will post here.

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Answer 8

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

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Answer 9

BobHarris

Level 9

52,838 points

Oct 26, 2020 12:25 PM in response to Gibbo777

Gibbo777 wrote:

I have exactly the same problem, and have attempted ALL of the above fixes. This only happened (to my knowledge) after the update. I have tried to re-pair the watch, deleted the keychains required, toggled keychain on and off, no matter what I do this just keeps on failing. I have logged out of iCloud, on all devices and logged back in. You name it, short of throwing my MacBook in a tub of sulphuric acid, I am all out of options. Has anyone managed to get a solid response from Apple yet regarding this problem, as it seems to be a growing number of people struggling with the same thing. Is there possibly a keychain virus that has wangled its way in? I would love some assistance. Apple Watch 3 and MacBook Pro. All running latest softwares.

Any help would be great, many thanks.

G

Mine seems to be working today.!

But yesterday, I went through the Keychain and ~/Library/Sharing/AutoUnlock deletes, plus disabling iCloud Keychain syncing, and a reboot.

After that my personal Mac worked once, then stopped. My company Mac did not work.

TODAY, I read another post about it working after clicking on the Allow Apple Watch to Unlock Mac option.

The first attempt at enabling, gave the cannot communicate. Clicked the Security option again, and this time it worked.

I've unlocked my personal Mac 4 or 5 times today, and my company Mac at least twice. But for just one instance, I had to enter my password, but after that it used the Apple Watch.

It has only been a few hours, but I'm hoping it has locked itself in.

My only guess is that it took a while for all the devices (Macs and iPhone) sharing the Keychain to finish exchanging updates with each other and settle done, so that it worked today.

Here is hoping it sticks for the rest of the day, and all the days that follow.

FYI: I did send Apple Watch feedback (https://apple.com/feedback), as well as file a developer bug with pointers to this thread.

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Answer 10

BobHarris

Level 9

52,838 points

Oct 31, 2020 2:33 PM in response to RedboneRambler

RedboneRambler wrote:

So, this works to a small extent, but whenever I try it, it will only allow my watch to unlock the computer once. After this, it disables the feature, and I have to go through the entire process again.

I found AFTER doing the steps in the current thread, that I needed to follow the steps in this reply over in this thread

https://discussions.apple.com/thread/251826134?answerId=253504359022#253504359022

I also found that it took awhile for the iCloud Keychain records to propagate and merge on all the systems. More so when you have multiple devices sharing the keychain (I have 4 Macs, the iPhone, and the Apple Watch). I followed both of the above threads, but it was not reliably working until the next day, when I tried again. And I did have to click the enable check box twice the next day, but then it stuck.

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Answer 11

Jan 7, 2021 3:47 PM in response to TiggerGTO

What worked for me was enabling the Airplane Mode and then disabling it again.

Before this, I tried the steps outlined here https://discussions.apple.com/thread/251826134?answerId=253529745022#253529745022 and restarted my Mac without success.

But once I did the Airplane Mode trick, it worked.

Reply

Answer 12

aagraw

Level 1

4 points

Oct 10, 2020 8:11 PM in response to TiggerGTO

Basically below are the steps:

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.
RESTART MAC and try

Reply

Answer 13

TiggerGTO Author

Level 1

90 points

Oct 12, 2020 12:51 PM in response to slothrop0000

I've done everything that I can think of at this point. This is roughly the order of what I did:

Updated watchOS and got battery problem
Unpaired / re-paired watch and phone -- fixed battery problem, but broke unlock Mac with watch
Tried every suggestion I could find on the Interwebs to try to fix this problem
Created this thread to see if I could get help from the community
Started a chat with Apple support
Escalated to the point where I had several phone conversations with a senior support advisor
1. We tried all the solutions that he could find
2. Finally got to the point where the next step was to reinstall macOS, which I did
3. Problem was still present, so he walked me through taking and submitting logs which he forwarded to engineering
Tried solution posted by mark__t including searching for and deleting the plist files
Solution didn't work until I restarted my Mac
Finally able to check the "Unlock with watch" option \o/
Contacted Apple support to try to follow up that I had a working solution from the community. After several tries, finally got a phone call from a different advisor. She sounded quite happy when I showed her this thread and told her that it fixed the problem for me and quite a few other people. I told her that it seemed like any competent engineer armed with the logs that I previously uploaded and the solution that fixed it for me should be able to figure out what's wrong and how to fix it in a subsequent macOS update.
Responded to several people like you to suggest things to try if the solution didn't work for you and to reiterate that I have provided both logs and a working solution to Apple for this problem.
Hope that in the near future Apple includes a fix for this in a macOS update.

So, there is nothing else I can do to "keep us posted." I'm not trying to be snide or anything, but through other people's responses to this thread, I have found a solution that worked for me, and I've done everything I can think of to help others find this solution including Apple support.

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Answer 14

Oct 20, 2020 2:51 AM in response to danmitchell

So I followed this thread and I've fixed my problem. Hopefully this'll help some of you.

For reference I am currently using iPhone 11 with iOS 14 and Apple Watch Series 5 with Watch OS 7. This issue was appearing in Catalina but also occurred when I started beta testing Big Sur, therefore I assume this solution will work for both MacOS versions.

Firstly I followed the KeyChain reset steps above (thank you Mark_T)

Steps (follow at your own discretion)

1. Open "Keychain Access"
2. In "View", enable "Show Invisible Items"
3. Search for "Auto Unlock"
4. You should see a whole bunch of application passwords for "Auto Unlock: XXXX's ..."
5. Select all records and delete (this will reset/disable auto unlock on other Macs if you use multiple Macs)
6. Whilst still in "Keychain Access", search for "AutoUnlock" (no space)
7. There should be 4 entries for "tlk" "tlk-nonsync" "classA" "classC"
8. Select 4 records and delete (don't worry if they re-appear, the system repairs this automatically)
9. Open "Finder" and navigate to "~/Library/Sharing/AutoUnlock" (Copy and paste this in Go To Folder without quote marks, to find the files)
10. There should be two files "ltk.plist" and "pairing-records.plist"
11. Delete both files
12. Open "System Preferences" and try enabling auto unlock. You may need to enable it twice, the first attempt will fail.

This didn't work on its own for me so I followed the advice of others as well, as follows

Go to System preferences and click in to icloud and disable keychain

reboot the mac

don't enable keychain yet

Got to System Preferences, Security and Privacy and tick the box to enable unlock with Apple Watch

This will produce the error (I think it resets something because Keychain is not enabled)

Go back to icloud settings and enable Keychain, wait for it to enable

Back in Security and Privacy, tick the box to enable unlock with Apple Watch

Finally solved my problem. Thanks to all for contributing.

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Answer 15

Macca59

Level 1

8 points

Nov 2, 2020 11:05 PM in response to Wally Flannigan84

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.

Reply