os stuck at preparing watchos 10.3 update

I rebooted twice, not a solution. Here's the issue - there was a very short-lived notification popping up, asking for the apple watch to be unlocked (which it shouldn't as it is on the charger), so I took it off the charger for a second and entered the 4-digit code, then placed it back on charger, now the update is downloading normally.

I deleted the update by going to Apple Watch App on my iPhone and then general then storage then delete the current download. Then I restarted my iPhone and Apple Watch at the same time then I restarted the update process 10.3 again and my watch updated without a hitch

After updating my iPhone 15 Pro to 17.3, I attempted to update my Ultra 2 watch to Watch OS 10.3 and encountered the same problem: the installation stalling during the preparation phase. I rebooted both the iPhone and the watch. Although it took another hour, the update was eventually successful, and everything is working fine now.

I had the same problem, but after rebooting iPhone 12 and Watch ultra 2 and an after toggling the auto update button and with the watch fully charged, finally the update was done when I woke up.

Finally, I fixed it, I had to turn off the phone and the watch and restart both again.

make sure the watch is on the charger.

It tries to install automatically but it disconnected from the charger while installing.

Open Apple watch app on iPhone, tap General, scroll down to Storage, open. There should be a choice to delete the update.

iPhone 14 Pro running iOS 17.3,  Watch 7. Tried restarting both, but no joy, twice: progress bar remained on "preparing" whether auto update was on or off. Both devices were being charged by an Ohlpro 3-in-1 Foldable MagSafe wireless charging station. Finally switched to the MagSafe Duo charger (larger footprint) and Bob is now my uncle.

you don't have to delete anything,

after reboot the phone and the watch.

make sure the watch is on the charger.

do the update again, now it installed.

Had the same problem with Apple Watch Series 8 os 10.3 update. I deleted the update file, rebooted my iPhone 13 Pro, my watch, and then re installed the update....the only way it would complete was if I kept toggling the auto update button. Both devices were fully charged.

When I went to Settings>General>iPhone Storage there was no option for deleting an update so I continued restarting my watch until it displayed a message that I’d seen earlier and canceled. This time I chose the other option and the software installation resumed and completed

Mine is iPhone 14 and Watch SE (2nd gen). It’s stuck on Apple Logo with the progress dial that encircles the logo. Watch App says the update was installed. I followed the things others have found successful but so far, nothing changes. Restarted the watch several times then both watch and phone. Both were charging and within inches of each other when the update was happening and I only noticed after putting on my watch this morning. I can’t even unpair it and repair to phone. Any other ideas?

I'm another stuck on preparing. No progress at all in about two hours.

Me too. I’m stuck at preparing with no progress after over two hours.