I follow all directions and watch will no go past 50% preparing upgrade. Deleted download, Shut off phone and watch and still nothing. Left watch on charger and attempted to upgrade again last night. Good WiFi signal and after 8 hours still at 50%
Apple Watch Series 8, watchOS 10
I've experienced exactly the same issue and spent hours yesterday (April 12) on Apple support chats and support phone calls. Clearly many people have complained about the issue with the latest WatchOS update. This morning I updated my wife's iPhone to 17.4 and watch to 10.4. What I noticed was the 10.4 update file yesterday was 1.1 GB whereas today it was 1.09GB. The watch update for her watch went smoothly so I retried with mine. It also completed smoothly - as one would expect. Clearly Apple engineers have implemented an update to the 10.4 code to resolve whatever "incompatibility" existed. My battery usage is now back to normal because the watch is not "stuck" in Preparing. Try the download today. Hope you have the same experience as I did today.
Have an update to previous post.
I unpaired the watch from my phone. Paired it back and it then updated to 10.4.
I did all of that unpairing, resetting stuff yesterday to no avail. Updates should not be this onerous.
Can’t update to watch OS 10.4
