Apple Watch Series 12 Unexpected Restart, Kernel Panic

You should contact the official Apple Support about that, they can diagnose your watch online.

Contact Apple Support - Apple Support

Before you do that, try to erase the watch and set it up as a new device without using any backup data. Then test it again. You will only lose your created watch faces and may have to add the cards in the Wallet app again.

Unpair and erase your Apple Watch - Apple Support

The same happens on series 12. I contacted Apple; they ran 2x diagnostics and said the hardware is perfectly fine. It randomly shut down 2x while I was just looking at notifications. They made me reset the watch, looks like it's a watchOS 27 issue wide spreaded.

If you did not use an Apple Watch before, there are no backups you can restore from, that is correct.

Your Apple Watch is covered by the One-Year Apple Warranty, which also includes the hardware.

In case Apple diagnosed your watch, they have also downloaded the diagnostic reports, so that Apple Techs can take a look at those and find the reason for this issue.

Until they come up with a fix, monitoring the behaviour of the Apple Watch 12 is the only thing you can do as a user.

Any 3rd party apps installed? If yes, try to use the watch without those and see if the crashes stop.

Chatted with a tech and they had me delete VPN profiles and then force restart both phone and watch.

They have asked me to unpair and then pair again. I haven’t done that step yet as the restart seems to be working. Will advise if it doesn’t.

Everybody having this issue with the new Apple Watch models should let Apple Techs know directly about it by using the Feedback link, as this is the only way to reach them. The more users do that, the more likely is a fix in an upcoming update, in case this is software related.

Feedback - Apple Watch - Apple

I had 4 reboots on my Ultra 4 on Friday when I first got the watch. Did a hard reset/reboot and everything seemed fine until Sunday, when the watch started rebooting again randomly. Called Apple, they had me go to the nearest Apple store which I did this morning and exchanged the watch to another new unopened Ultra 4. Wish I knew about this post before making the trip!

Clicking the "Me too" button does not make Apple Techs aware of these issues, the newer Apple Watch models seem to have.

Only using the Feedback link and filling out the form does.

The more users do that, the more likely is a fix in an upcoming update.

Feedback - Apple Watch - Apple

You can go to your Watch app (on iOS) > General > Diagnostics logs > there you will be able to download a file and then air drop it or upload it from your iPhone via Feedback Assistant

Same problem here. It’s a widespread problem. There also posts about this on the MacRumors Forum and Reddit.

https://forums.macrumors.com/threads/ultra-4-rebooting-randomly.2489837/?post=34807923#post-34807923

https://www.reddit.com/r/AppleWatch/s/O2V7pAiN0o

Same with my new Ultra 4. WatchOS is up to date, watch is set up as brand new. Got a first reboot after first 2-3 hours of usage.

I've added a feedback via Apple Feedback website and via Feedback Assistant

Same issue here on Ultra 4 Happened 3 times. I force rebooted it too. Investigating and checking logs for further crashes.

it happened before and After day 1 update.

{"bug_type":"210","timestamp":"2026-09-19 13:19:13.00 +0200","os_version":"Watch OS 27.0 (24R364)","roots_installed":0,"incident_id":"9EE2A0C9-46E2-46CE-A1A0-CC3AEEF2251E"}

Me and hubby have just bought and Ultra each and both of them have rebooted today.

i have the same issue with My Apple Watch 4 Natural Titanium, it only happen when using iMessage when texting