New Apple Watch Series 12 and Apple Watch Ultra 4 owners are reporting unexpected reboots, and several shared diagnostic logs point to the same Apple Neural Engine timeout.
The reports began appearing shortly after the watches went on sale Friday. Owners say their watches can suddenly show the Apple logo and restart while using features such as Siri AI, Maps, the App Store, phone calls and workouts. Some have also reported reboots while the watch was idle.
Neural Engine Timeout Appears In Multiple Crash Logs
At least four owners have shared “panic-full” diagnostic logs showing a similar Neural Engine timeout.
The logs indicate that the Neural Engine stops responding for roughly two seconds before a firmware watchdog detects the timeout. The watchdog then triggers a kernel panic, causing the Apple Watch to restart.
This does not prove that every reported reboot has the same cause, but the repeated Neural Engine timeout in multiple logs is a specific piece of evidence that stands out from the user reports.
Both New Apple Watch Models Are Affected
Reports have appeared from owners of both the Apple Watch Series 12 and Apple Watch Ultra 4.
The reboots have happened during a range of activities, including editing watch faces, using Siri AI, opening Maps or the App Store, starting phone calls and recording workouts. Other owners say their watches restarted without any obvious action taking place.
The MacRumors forum thread has received reports from around 30 owners so far. Similar complaints have also appeared on Reddit:
I received my Apple Watch Ultra 4 on Friday, and it has already rebooted on its own five times. The diagnostic reports all show the same error: ANEHWDevice::ANE Timeout. Apple Support suggested that the initial pairing may have gone wrong, so I unpaired the watch, erased it completely, and set it up as a new Apple Watch without restoring a backup.
Unfortunately, it rebooted again after the clean setup, with the exact same error.
Apple has logged my case, and I’ll contact them tomorrow to request an exchange. I’m just concerned that a replacement might have the same issue if this turns out to be a watchOS or firmware bug.
That does not show how widespread the problem is among all Series 12 and Ultra 4 owners. The reports only represent users who have encountered the issue and chosen to report it online.
The Problem Can Happen On watchOS 27.0
Some affected watches reportedly rebooted on the original watchOS 27.0 software as well as the update installed during the initial setup process.
Several owners have also erased their watches and set them up as new devices, but continued to experience reboots. One Series 12 owner reported that a replacement unit developed the same Neural Engine panic.
Those reports make a problem with restored data or an individual user’s settings less obvious as an explanation, although they do not establish the underlying cause.
Apple Has Not Confirmed The Problem
Apple has not publicly acknowledged the reported reboots or confirmed that the Neural Engine is responsible.
The available evidence currently consists of owner reports and diagnostic logs shared online. The repeated timeout is worth noting, but a larger set of logs or an official response would be needed to establish whether there is a specific hardware or software bug affecting the new watches.
What To Do If Your Apple Watch Keeps Restarting
If your Series 12 or Ultra 4 keeps rebooting, you can check its diagnostic logs by opening Settings > Privacy & Security > Analytics & Improvements > Analytics Data and looking for files with names such as “panic-full.”
Keep the watch updated as Apple releases new versions of watchOS. If the restarts continue, note what you were doing when they occurred and contact Apple Support. Saving relevant diagnostic information can also be useful when reporting the problem.
For now, the reported Neural Engine timeout provides a possible explanation for at least some of the crashes, but Apple has not confirmed the cause or the scope of the issue.
