Apple stops WatchOS 5.1 update rollout following reports of bricked Apple Watch devices6
The issue is affecting some Apple Watch Series 4 units. If you happen to own one of these and have only downloaded the patch, do not proceed with installing it. Apple has also released an official statement on the matter:
Some of the main features of WatchOS 5.1 include support for Group FaceTime via FaceTime Audio alongside a set of single color watch faces. The update also introduces more than 70 new emoji characters. As mentioned above, we should expect a revised version to be pushed out soon, so stay tuned for all the latest developments.