Apple Watch Series 9 reboots randomly after WatchOS 26.1 update

Apple Watch Series 9 is randomly rebooting after WatchOS 26.1 update. My model is GPS only.


I've tried unpairing, reset to factory settings with, and then without using a backup. I've uninstalled all third party apps. Even let the battery drain completely (although after 12hs of no charge it was still showing the time and the charge logo when I pushed the side button).


I've had this watch for 1 year and 10 months. I've never experienced this TBH.


Any recommendations?


I'm waiting for a next OS update to see if it fixes it.

Posted on Nov 23, 2025 4:37 AM

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Question marked as Top-ranking reply

Posted on Nov 23, 2025 7:03 AM

Battery health is at 89%. Now, I was able to get a hold of the ips logs. One of them is huge, but I got them analyzed by chatGPT and this is what I got back, so I'm inclined to go get a DFU reflash:


1. The panic log (panic-full…ips)


Even though the raw text is massive and partially truncated in the export, the key line does show up:


AOP PANIC


That’s the big clue.


AOP = Always-On Processor, a tiny low-power co-processor inside the Watch responsible for background tasks like screen-on movement, sensors, sleep tracking, etc.

An AOP panic means:



  • The Always-On Processor hit an unrecoverable error
  • The device had no choice but to reboot


This is almost never caused by an app. It’s usually:


  • A firmware bug in watchOS
  • A corrupted OS image (often after an update)
  • Rarely, a failing sensor or internal hardware fault


2. The OTA update log (OTAUpdate…ips)


This one is super telling.


You’ve got this error:


MobileSoftwareUpdateErrorDomain error 78


Update finish took too long since apply finish event

Translation:


Your Watch tried to finish applying a WatchOS update, got stuck, and basically never completed cleanly.

So your Watch believes it's updated, but at a low level the update process froze or left some parts in an inconsistent state.


That alone can absolutely cause AOP crashes.


3. The reset counter (ResetCounter…ips)


Shows:


  • Reset count: 1
  • No boot faults
  • No thermal shutdowns


That means:


  • The Watch isn’t power-cycling due to heat or battery failure
  • It’s rebooting only when the AOP panics
  • This is not a battery or overheating issue


⭐ My recommendation for you, personally



👉 Unpair → re-pair → monitor for 48 hours.


If the Watch still reboots randomly, then:


👉 Apple Store for DFU reflash.

You’re almost certainly not dealing with a dying Watch.


11 replies
Question marked as Top-ranking reply

Nov 23, 2025 7:03 AM in response to Ingo2711

Battery health is at 89%. Now, I was able to get a hold of the ips logs. One of them is huge, but I got them analyzed by chatGPT and this is what I got back, so I'm inclined to go get a DFU reflash:


1. The panic log (panic-full…ips)


Even though the raw text is massive and partially truncated in the export, the key line does show up:


AOP PANIC


That’s the big clue.


AOP = Always-On Processor, a tiny low-power co-processor inside the Watch responsible for background tasks like screen-on movement, sensors, sleep tracking, etc.

An AOP panic means:



  • The Always-On Processor hit an unrecoverable error
  • The device had no choice but to reboot


This is almost never caused by an app. It’s usually:


  • A firmware bug in watchOS
  • A corrupted OS image (often after an update)
  • Rarely, a failing sensor or internal hardware fault


2. The OTA update log (OTAUpdate…ips)


This one is super telling.


You’ve got this error:


MobileSoftwareUpdateErrorDomain error 78


Update finish took too long since apply finish event

Translation:


Your Watch tried to finish applying a WatchOS update, got stuck, and basically never completed cleanly.

So your Watch believes it's updated, but at a low level the update process froze or left some parts in an inconsistent state.


That alone can absolutely cause AOP crashes.


3. The reset counter (ResetCounter…ips)


Shows:


  • Reset count: 1
  • No boot faults
  • No thermal shutdowns


That means:


  • The Watch isn’t power-cycling due to heat or battery failure
  • It’s rebooting only when the AOP panics
  • This is not a battery or overheating issue


⭐ My recommendation for you, personally



👉 Unpair → re-pair → monitor for 48 hours.


If the Watch still reboots randomly, then:


👉 Apple Store for DFU reflash.

You’re almost certainly not dealing with a dying Watch.


Nov 24, 2025 2:02 PM in response to Ingo2711

Well, I took it to one of the official reseller stores and they didn’t find anything specific running diagnostics.


They could take it in for $40 and run some complete diagnostics but they said that most likely I will need a new one and it will cost me almost as much as a new one.


They did offer me advice. That I try to pair the watch with another iPhone because two weeks ago I switched from an iPhone 12 to an iPhone 16.


i’m currently testing the watch paired to an iPhone 15 that my wife has.

Nov 26, 2025 4:17 AM in response to Ingo2711

I have now tried pairing a newly setup watch and the iPhone is also setup from a clean install (not from a backup). Pairing it with my wife’s iPhone as well. None worked, same error.


Also, in the many resets I’ve performed, sometimes it will require me to update WatchOS before setting up the watch. Which is weird because it is already in the latest version. I couldn’t skip this, but as soon as I accepted, it will load a bit and then “you’re already up to date “. However, this hasn’t happened every single time reset to factory settings.


So the chatGPT suggestion still seems plausible and now I have one more shot: wait until WatchOS 26.2.

Apple Watch Series 9 reboots randomly after WatchOS 26.1 update

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