My download of Apple watchOS 10.4 STOPPED during "preparing" and won't advance.

15 pro max + series 9. I tried reboots, deleting and redownloading several times. After I removed my card from the apple pay and downloaded a new watch face it worked. 10.4 yay. I would expect a different user experience though after paying 2 kilos.

restart both devices

restart the update

CHANGE YOUR WATCH FACE

…no really… apparently that works…

See the 'Need more help with updating?' section in:

Update your Apple Watch - Apple Support

I’m not sure about your case. But mine, I re-start my Apple Watch Ultra 2 and at the same time I re start my iPhone. Everything settle within 1.5 hours with the download and watch OS installed

This worked for me too! After getting stuck on preparing download for 10 hours with multiple restarts to my phone and watch, I simply change the face and preparing finished almost immediately!

this worked for me too. After many many tries. Restarting iPhone and watch before installing seems to work, of course deleting previous attempts from storage.

what a pain.

After I deleted the update on my iPhone in the Apple Watch app and rebooted it took about 45 minutes for the progress bar to move. It’s nearing the end. I would say just start it and don’t watch the Apple Watch update screen. By reading this forum three pages it jumped from 60% preparing to 85% preparing. Good luck and total BS we have this update troubles for what we have paid for these devices. iPhone 15pro max and Apple Watch series Ultra 2.

Trust when people are saying to just LEAVE it alone. I was going crazy restarting my phone and watch. I followed the “leave it alone. It takes awhile”. It does take awhile. And now my watch is updated. Finally. Hope this helps

Thanks. this works. I had same issue on 11 Pro, after deleting update file on Apple Wach, I restarted both iPhone and Watch, then tried again, download was much quicker, but still it took time at "50% preparing". Left it like you said, probably one about 30mins, and when I checked all was done.

Mine finally worked after restarting watch and Iphone

I restart both of the devices (iPhone and Apple Watch) and start the update.

i let it during the night and today it was done👍🏻

Under airplane mode I selected mirror iPhone and the update progressed quickly and installed.

I have an iPhone 15 pro

watch series 9

I had this issue and a reboot of watch and phone resolved it.

You should also try deleted 10.4 in storage on watch before it installs. then try again.

Yes. You are right. Needed to take longer time to download especially during the phone in “preparing “ status. Just leave it for 1.5 hours and it will automatically install the watch is 10.4.