Your Mac was unable to communicate with your Apple Watch.

Hello fellow sufferers. I realise this Discussion has got to page 21. I too have tried everything I can think of (thank you to Mark for your 12-step procedure. Thank you to all you agents in Apple Support for your valiant efforts). But nothing has worked for me.

Two days ago I thought of something I had not tried since getting WatchOS 7.1: restart the watch. And that has worked for me. Both our watches now unlock both our Macs. And it has stuck so far for 48 hours…

Thanks for the suggestion, but restarting the watch and the iPhone was one of the first things I tried early on.

I reported recently that the steps above, plus unlinking, then relinking the watch has mostly solved my problems.

That lasted about two days. Now it is back to the watch not unlocking the iMac 100% of the time.

Thanks, Lawrence. Like you I went through the full gamut when the problem first started. Then, when WatchOS 7.1 arrived, the unlocking of our Macs started intermittently. It was only then that I thought of restarting the watch. I wonder if that was the crucial step - and I wonder too, of course, whether it will all turn to worms after a couple of days. The behaviour is rather like an old analog device…

I had the same problem today and I tried all the solutions posted before, but no one worked.

What I did to solve the issue is signing out from iCloud on my Macbook after following the steps proposed by mark__t and the rebooting it while signed off.

After the reboot I signed in again with my Apple ID and the Auto Unlock functionality started to work again.

Maybe someone else could find my steps useful.

I used a combination of approaches including ones from mark_t, duZ3N, and also unpaired re-paired Apple Watch. Then tried to re-enable unlock Mac from Apple Watch: failed the first time, worked the second time. All seems good now.

Is there any solution finally for this  watch not communicating with the Mac? I tried all the above steps but it did not help? Any more suggestions that you guys got from engineering who ever has escalated it?

Try to Reset default keychains, this fixed my issue. check my solution above.

After 2-3 hour debugging, I fixed by "Reset default Keychains" from Keychain Access app > Preference, logout your user and make sure to enable Keychain again from Mac iCloud

What is the version number of the new updates? My Apple Watch 4 will not communicate with either my iPhone 12 Pro or my MacBook Pro. All 3 devices say they have the most recent version of the operating systems.

Sadly, no matter how many times I tried the above 12 step solution - it didn't work.

What finally worked for me - was:

1) Sign out of iCloud on my Mac

2) Reboot

3) Sign in to iCloud on my Mac

4) Reboot (not sure if this step was necessary, I did it to be safe)

5) Enable open with Apple Watch in settings

Et Voila - Success

I have had this same issue and had no luck with any of the solutions I found in this thread. What finally worked was unlocking my watch AND my iPhone, then selecting "Use your Apple Watch to unlock apps and your Mac."

Hi all,

I recently starting having this issue around when I updated to Big Sur and have been ignoring it until today.

What I did unpair and repair my phone.

First, do a backup (I backed mine up to my laptop, I think you can do iCloud as well, but I prefer a hard backup) of your iphone to your mac.

Next, I unpaired my watch, which basically resets it back to factory default.

On the Mac, I opened Keychain Access and deleted the files noted in mark_t's comments (in addition to the passwords for apple watch). Then I deleted the preferences per his instructions and restarted my mac.

On the watch, I re-paired my watch to my iPhone.

Once re-pairing was complete, I went into preferences, security and privacy- and clicked on the option to unlock. It failed the first time, but was successful the second time.

Hope that helps someone here.

This worked for me! I tried the "12 step" solution a couple of times, and it didn't solve the issue (Big Sur 11.0.x, Watch OS 7.1). I then upgraded to Big Sur 11.1, then on my Mac signed out of iCloud, rebooted, and signed back in to iCloud...and then enabled Apple Watch in security settings on the Mac. All worked. Thanks!

"Unable to connect to watch" problem arose when I transitioned from iPhone 11 to 12 pro max. Using series 5 watch, new iMac. Same problem with watch unable to open my MacBook. I tried everything I could find in the discussion groups: deleting keychain access files and related, unpairing and pairing watch as new, factory reset on watch, etc, etc, etc. Over and over.

This finally worked for me. On both the iMac and MacBook, deleted the iCloud account. Then re-added iCloud on each. (I had local contact files, etc, kept on the machines.) When then trying to check the "Use your Apple Watch ..." box in Security & Privacy, did bump into a message that my Apple Account settings needed to be updated/verified. Took care of that. And, low and behold, can check that pesky "Use your Apple Watch ..." box on both the iMac and the MacBook. And, watch does do its thing when I need to log into either.

Hi I had this problem and ended up on this thread. There's a few useful solutions but a simpler one worked for me: I had to have both my Watch and my iPhone unlocked for the changes to take effect.

Hope this helps!

Steve

I tried the 12 step method of mark_t a few times: No success.

My solution:

I Found some old Watch passwords

Deleted old Watch passwords in Keychain

1 open KeychainAccess

2 View -> Show invisible items

4 Search for "Watch"

5 Delete: "Apple Watch ......." (Apple Watch Name)

6 Set SystemPref for unlocking Mac. I had to do this two times