Apple Watch Series 12 and Ultra 4 get fix for random restarts

Apple has released watchOS 27.0.1 for the Apple Watch Series 12 and Ultra 4, with one very specific problem in its sights: unexpected restarts. It arrives only days after owners of Apple’s newest watches started reporting seemingly random reboots.

A very specific watchOS update

Unusually, the firmware update is only available for the Series 12 and Ultra 4. Apple’s release notes are about as straightforward as they get, saying the update fixes an issue where Apple Watch may restart unexpectedly.

We covered the issue earlier this week. Series 12 and Ultra 4 owners had reported their watches suddenly showing the Apple logo and restarting, sometimes while actively using the watch and sometimes while it appeared to be doing very little.

The crashes were not tied to one obvious activity. Reports included reboots while using Siri, Maps, the App Store and watch faces, as well as during workouts. Some happened while the watch was apparently idle, which made finding a simple trigger difficult.

More importantly, several diagnostic logs shared by affected owners pointed toward the same Apple Neural Engine timeout. In those cases, the Neural Engine appeared to stop responding before a watchdog triggered a kernel panic and restarted the watch.

Apple moved quickly on this one

The two watches only went on sale on September 18, so the turnaround here was pretty quick. Reports started appearing almost immediately, and the dedicated patch followed less than a week after launch.

It also strengthens the likelihood that this was a software or firmware problem rather than something owners needed to solve by exchanging their watches. Some affected users had already tried wiping their Apple Watch and setting it up again, while at least one report involved the same problem appearing on a replacement unit.

That said, Apple only says the update fixes the unexpected restart issue. It has not published a detailed explanation of what changed.

For anyone affected, though, installing watchOS 27.0.1 is the obvious move before doing anything else. Apple says updates can be installed directly from the watch through Settings, General and Software Update, or through the Watch app on the paired iPhone. The watch needs at least 50 percent battery and should remain on its charger while the update installs.