Apple’s watchOS 27.0.1 update has arrived with a fix that prevents Apple Watch Ultra 4 and Apple Watch Series 12 models from randomly restarting.
On Wednesday, just over a week after watchOS 27.0 hit the general public, Apple rolled out the watchOS 27.0.1 update. The software fixes a bug that caused Apple Watch Series 12 and Apple Watch Ultra 4 to restart unexpectedly.
Those who encountered the now-resolved issue said their Apple Watch rebooted when changing faces, making calls, using Siri’s AI, opening Apple Maps or the App Store, and recording workouts. Some Apple Watch owners even claimed that their devices rebooted when idle.
As for what caused the reboot bug on watchOS 27.0, a post on the Apple forum outlined a Neural Engine timeout on an affected Apple Watch model. In short, a Neural Engine command waited 2,020 milliseconds, exceeding the 2,000 millisecond limit, after which the device rebooted.
While the watchOS 27.0.1 update fixed these spontaneous reboots, Apple hasn’t revealed what caused them.
The company’s website states that there are no CVE (Common Vulnerabilities and Exposures) entries associated with watchOS 27.0.1. This suggests that the software likely does not include important security fixes and that this version has not fixed any significant vulnerabilities.
The same page also points out that watchOS 27.0.1 is only available for Apple Watch Ultra 4 and Apple Watch Series 12. In short, this is a bug fix update for the 2026 Apple Watch lineup.
How to update to watchOS 27.0.1
- Make sure your Apple Watch is at least 50% charged and connected to Wi-Fi
- On your Apple Watch, open the Settings app
- Tap General
- Tap Software Update
- Tap Install if a software update is available
- Follow the on-screen instructions
How to update to watchOS 27.0.1 via iPhone
- Make sure your watch is 50% charged and connected to Wi-Fi
- On your iPhone, open the Apple Watch app
- Tap General
- Tap Software Update
- Download the update if it is available
- Follow the on-screen instructions
