apple watch won't unlock Mac

Problem was resolved yesterday evening.

The issue was the watch was not on WiFi.

We had some issues with wireless connectivity and I had been troubleshooting that for the past few days.

(Note: a single bad ethernet cable can disrupt an entire wired/wireless network.)

Using a network analysis tool from an Irish company whose name rhymes with Thing, I could see my phone had an IP, however the watch also needs an address.

So, I unlinked my watch from my phone, and rebooted the watch.

Helpfully, I received a security alert that a new device was on my network (the watch).

After relinking watch to phone, it now functions properly.

*It might have been possible to simply restart the watch to obtain the same result.

This happened to me after the 14.2.1 (23C71) M2 macBook Air system update and , 10.2 watch update. In my case the watch showed in settings regardless if it was on.

The How to: Unlock your Mac with your Apple Watch - Apple Support. didn't work however adding shutting off the watch along with it did:

1. Shutdown the watch.
2. Turn off the apple watch setting on the mac as described in the link.
3. Shutdown the mac as described in the link.
4. Turn on the mac as described in the link.
5. Open the apple watch setting on the mac as described but leave unchecked. The watch may show even though its off.
6. Turn on the watch.
7. After the watch is completely booted and unlocked switch on the apple watch setting in the mac settings.

This does seem to work, but the link to Apple Support is unhelpful and superfluous.

1. Shutdown the Watch
2. In your Mac: "Touch ID and Password" (within System Settings) attempt to turn on "Use Apple Watch to unlock your applications and your Mac." It will fail with a FUBAR message about signing into iCloud
3. Restart the Mac
4. Sign into Mac after restart; let the restart fully finish. THEN put Mac to sleep (or close the laptop).
5. Restart the Apple Watch and unlock the Watch (Watch password)
6. Wake up the Mac and sign in. Check "Touch ID and Password" within System Settings. It should show that "Use Apple Watch to unlock your applications and your Mac" is on. If so, the function is restored.

I *think* this is sound, except my experience with this bug over the years is that no simple fix is likely to keep working. Maybe I need correct incantations during some specific phase of the moon?

I never restart my Mac until weird things start happening that suggest that the OS's working memory has been corrupted in some way (as in the OS insists that there is not Internet modem, for instance). The sudden failure of my Apple Watch to unlock my Mac *appears* to be one of those corruptions that requires a bit more than simply restarting the Mac.

My issue was fixed as soon as I turned Wi-Fi back on. I had forgotten that that was necessary to unlock Macs. I was trying to hypermile with my battery and turn off Wi-Fi to save power.

Hi interrobang ... wondering if you checked your iMac supports auto-unlock:

(ie: We do not know which iMac model (year) you are using)

From the article you referred to:

says:

"If you're not sure whether your Mac supports Auto Unlock,

✽  press and hold the Option key

while choosing Apple menu  > System Information.

✽  Select Wi-Fi in the sidebar of System Information.

✽  On the right side, look for ”Auto Unlock: Supported.”

_______________________________________________________________________

Re: "I presume for auto login to work, my Mac needs to have a Bluetooth connection with one, or both".

Please check that your iMac and Apple Watch have Wi-Fi and Bluetooth turned on.

NB:

The first time you log in after you've turned on, restarted or logged out of your Mac, you must enter your password manually. After that, Apple Watch can log in for you.

_____________________________________

Seems there was an issue with auto-unlock: was resolved with macOS Ventura 13.4

Info: What's new in the updates for macOS Ventura - Apple Support

You may want to send feedback to Apple if the issue persists on your iMac version:

Feedback - iMac - Apple

____________________________________________________

Re: "If I attempt to pair my phone with my Mac ... ":

This is quite another issue : (The author is discussing auto-unlock Apple Watch.)

You may want to view the excellent answer provided in the discussion thread below:

In attempting to pair my iPhone, iMac and… - Apple Community

else: you might want to begin a new discussion using the "Ask the Community"link at the top of this author's discussion thread.

All the best :-)

I came her to see this! I took my Ultra 2 off WiFi to save battery and didn't connect the two until seeing this thread.

I put watch back on WiFi and voila!

Hi CMatheso,

welcome to the Apple (user-to-user) Community.

Re: "apple watch won't unlock Mac"

Apple support has a January 31, 2023 article online that may be helpful in checking requirements etc.

How to: Unlock your Mac with your Apple Watch - Apple Support

All the best :-)

In each instance you should confirm that your watch is connected to WiFi. You may need a network diagnostic tool to see what devices are connected to your network.

I install updates to MacOS, iOS, and WatchOS as soon as they are released. For YEARS (I own a Watch 5) the Watch will unlock my Mac after the updates for some period of time (sometimes days, sometimes weeks) THEN it mysteriously stops. Occasionally, it will recover if I restart all three devices, but I have NOT FOUND a CONSISTENT pattern to get it working agains. Sometimes, I get up in the morning, and the function has mysteriously returned.

What drives me nuts, is trying to turn it pack on in System Settings produces this bogus message:

1) The Watch IS sounded into the same AppleID as iCloud, Mac, and iPhone. 2) There is NO OPTION in the Apple Watch app to sign into iCloud since at least the release of Watch 5.

I can't help but conclude that this bug has plagued users since at least 2017 and Apple has paid zero attention to it.

Seems the unlock difficulty may be caused by the Watch not being linked to both Bluetooth and Wi-Fi at the time. If you read through the discussion, C Matheso describes the fix that worked in that case, if the wi-fi connection drops out.

Re: "No option in the Apple Watch app to sign into iCloud":

The message says:

"You can sign in using the Apple Watch app on your iPhone."

Good to hear you solved the situation, interrobang! Thank you kindly for your reply, and for sharing the details of your solution. Cheers !

Certain features that require a mobile phone number won’t work on cellular models of Apple Watch unless you sign in to iCloud. Tap General > Apple ID, then sign in.

Same issue, login had worked for Mac and websites accessed in Safari (e.g., iCloud login).

Neither function works any longer.

27" iMac running Ventura 13.5.2

Apple Watch 5 running 9.6.2

iPhone Xs running 16.6.1

I note after reviewing the requirements as outlined here and checking System Information > Bluetooth that neither my phone, nor my watch are connected.

I presume for auto login to work, my Mac needs to have a Bluetooth connection with one, or both.

If I attempt to pair my phone with my Mac, it briefly appears in the list of Bluetooth devices in OS X System Preferences, and on my phone in Bluetooth preferences, and disappears just as quickly. If it persists long enough on my phone to click the [Connect] button, I am presented with a “Pairing Unsuccessful” screen:

I’m at a loss.

1. The Watch IS and ALWAYS HAS BEEN on both Bluetooth and WiFi. It works or doesn't willy-nilly with not a single change in any setting.

1. Is there an Apple Watch app that is NOT on your iPhone? Look at your Apple Watch app, wherever you find it, and see if there is any way to sign into iCloud.