The message "Your Mac was unable to communicate with your Apple Watch" Keeps appearing when I try to set up my Watch to unlock my MacBook Pro

This is what worked for me on my second Watch, a Series 1 which was already working fine on my Mac Pro but would just spin and spin on my new MBPr w Touch Bar. My original Watch was enabled immediately which is why the failure on the second Watch was driving me crazy.

I tried all of the above without success. I toggled the airplane mode on and off on my watch, which also toggled the same mode on my iPhone. Over and over, then I went to iCloud and signed out. (Very frightening) Signed back into iCloud and hoped all my docs and settings returned. Finally went back to System Preferences, Security and Privacy and clicked the box. The message appears again. Then I noticed that Bluetooth and iCloud were turned off on my iPhone. After checking all of the settings on the iPhone, I went back and clicked the box. I waited again for the dreaded notice, but it did not appear. Furthermore, the box stayed checked. Testing the unlock feature... IT WORKED AGAIN

My fix was making my keychain password the same as my user account password.

Finder > keychain > right click "login" > "change password for login

Create your password here.

Then:

system preferences > "users and groups" > select your account and then click "Change password" > ensure your password is exactly the same as you entered on the keychain.

Hope this helps!

I can attest that I tried everything and tried to debug this as best as I could.

From what I've seen I think it's either a Keychain issue or a enrollment validation problem from apple that is beyond my understanding. I'm inclining to think it's the Keychain.

Why do I say about enrollment? Because I had an apple watch series 2 that worked flawlessly with unlocking all my Macs from day 1. Unfortunately I had some problems with it, part of them from my fault, part from the device itself, and got it replaced under warranty. Although when I took the watch to the service, they had me to unpair it from the iPhone and also remove it from my appleid account, after replacing the watch (new device ID) and also after pairing it to my iPhone, I had for a while two watches listed under security preferences at the unlock section. I could not get any of them to unlock my MBP.

So I arrived to this thread and tried EVERY solution here. I even deleted, YES deleted my keychain from my Mac, but to no avail. Today I changed passwords from both my Mac and my Keychain (matching passwords) as some members suggested regarding the ASCII solution. Although my old passwords were ASCII compliant because they had usual letters and numbers and a character equal "=", which is ASCII compliant also, I decided to drop the "=" from my login password and my keychain password and miraculously it worked. Weird! Maybe it has to do with they keychain being synced across the devices and implicitly the MBP password.

Home I have an iMac that has the same old MBP password with the "=" sign in the password. I'll test home if the iMac works and get back later with an update.

Hopefully my insight helps others too.

I don't think it's a handoff problem or a icloud problem...moreover of a keychain problem. I confirm that resetting the keychain and having the same user pass with the keychain pass in ASCII should clear all bugs. Now my watch unlocks both my work MBP and my home iMac

For me the trick was changing the MacOs login/system password to the same as the one in iCloud. This somehow triggered some sync between the Mac and the iCloud and after that I could activate the Watch to unlock.

Before I also disabled KeyChain in the iCloud and then enabled it again, but only after changing the password I got it to work. I don't think the password has to be the same as the one in the iCloud account, but for me it did the trick.

WORKING ANSWER!!!

I tried all of these and Nothing worked. With iOS11 and High Sierra running my applewatch did not work anymore. HERE IT IS. Log out and log back into your icloud account on the Mac in question. It kind of makes a mess of stuff, BUT it DID work. My watch now unlocks my Mac.

I tried everything.

Changing Mac password

Disabling/enabing Handoff

Unpair/repair Watch

etc.

None of these helped because my Mac was looking for some outdated token on my Watch.

Finally reached out to Apple support. This worked:

1. System Preferences > iCloud > turn off Keychain

2. Keychain Access > Preferences > Reset My Default Keychains

3. Reboot Mac

4. You'll be asked to enter your iCloud password - enter it, then give iCloud time to sync up.

5. System Preferences > Security & Privacy > Click the lock to make changes (ensure it's UNLOCKED - if it already is, skip this step)

6. Check Allow your Apple Watch to unlock your Mac

I was going to reset the default keychains but got a warning I'd lose the keychain items, is that true? I don't relish the thought of having to rediscover all those passwords.

This worked perfectly since I got my first Apple watch, but then in the last week the battery started draining where I didn't get a full day on a charge. Tried a number of steps to fix it until I went nuclear and unpaired the watch then set it up as a new one. Everything works like it used to except this.

I'm just concerned I'm going to lose all my keychain entries and is there any way of getting them back (I kind of need that).

Thanks!

Yes that's true. Reseting keychain erases it and starts a new one blank.

Regarding keychain entries, as far as I know there isn't a method to export it all and import it afterwards.

Usually Keychain entries are found in:

/Library/Keychains

/Users/YourUserName/Library/Keychains

/System/Library/Keychains

Even if you are to export and import it back, or move folders entirely and move them back over the new keychain, you'd import the problem back too.

Another thing you can do is open KeyChain Access (spotlight it) and export items from there, especially passwords. For certs that would be much more complicated (public keys and you're probably gonna loose the private keys ).

Yes, they’ll be lost, but only for a moment.

If you had iCloud Keychain enabled, and disabled it before you reset your keychain, then your passwords will remain intact in iCloud Keychain and will be restored when you enter your iCloud password at the end of this process.

Follow this process end-to-end and you’ll be fine.

I did reset the keychain. Turned it off in iCloud on the computer before I did it. Basically I shot myself in the head, because not only did it not resolve my "unlock computer with watch" problem, but now all my passwords were gone.

I called Apple Support and they told me that even if I turn off Keychain for the cloud in my iCloud preference pane, it still wipes the keychain in the cloud.

Tried to restore the keychain from my Time Machine backup, but the only way to do that was to restore the entire system.

Naah. Called my ISP for help getting into my email, and I'll just have passwords reset and sent to me. I'll recreate it.

Just a word of caution for anyone thinking of wiping their keychain to get this resolved. Unless there is a right way of doing it that it will work, you could wind up with an even bigger mess.

Makes no sense.

If you had passwords stored in iCloud Keychain, turned off iCloud Keychain (this is required to protect your passwords) before resetting your keychain, then rebooted, entered your password, re-enabled iCloud Keychain, all your passwords would then be restored. This was recommended by Apple engineer and exactly my experience.

Perhaps re-try the process end-to-end?

Good luck.

I didn't have them last night - was working with Support to get them back. Failed, thought I'd try recreating them. This morning I was working with Support to find out why I was having trouble with one of my email addresses and while I was waiting for him to get a senior advisor I looked around and saw that keychain was still turned off in cloud. So I checked the box to at least back up my updated entries.

I checked just a few minutes ago and the entries were all there on my mac. You were right. I have my keychain entries back, but I still can't unlock my Mac with my watch any more (circling back to the topic of the thread).

The advisor I was talking to last night said she could help me with it but I said no, I just want my passwords back. I'm going to give it a few more days, try rebooting the watch and phone and computer then try it again. My problem is, I always get into a lot of trouble whenever I start fooling around with the cloud once I get it set up. 😟

My problem has been solved.

I wasn't logged into Facetime. Tried to log in then was told I had to log in to cloud again (after my misadventures with the keychain). Logged into both, tried to enable watch to unlock the mac and it just cranked trying to connect.

Then I forgot about it and had to go out for about an hour. Came back and moved my macbook pro from one spot to another, hitting the touch pad in the process. Then I felt a familiar tap on my wrist. it's working now.

Not sure if it was from not being logged into facetime or if there was a problem with my cloud login, but it's now resolved.

Yeah, if you repair your watch with the phone, you might not want to set it up as a new watch, that's where my problem started. I unpaired because the watch battery was draining at a prodigious rate and rebooting it didn't help. 😝