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

I experienced all of the above issues. It was finally resolved when I restarted my iPhone and watch and then turned Automatic updates on the watch off and then back on. This restarted the entire update process and it updated successfully.

I’ve turned off auto update

deleted download from storage

forced power down of iPhone and watch

powered up and then in watch app on iPhone asked it to apply update

it has now installed !!!!

hurray

should not be like this ….

I was having the same problem as everyone else with the pausing. So what I did was Reset my watch, (see Erase Apple Watch and settings) and then restored from backup. Tried updating to OS 10.4 again and I was updated in 40 minutes.

Ok, Ultra and 13 Iphone, same as everyone else. Waited several hours no luck, but I restarted the Ultra when the iPhone was stuck preparing, put it back on the charger, and zip, the preparing moved and went right up to complete and is being installed now - installing. Previously I restarted the iPhone, no luck, deleted storage, no luck -almost seems like the watch needed a jolt to start accepting it.. Hope that may help

1. Delete the watch 10.4 program in storage from the Watch App.

2. Set up “ Password Off” in the Watch App.

3. Reboot both iPhone and Watch.

4.Receive and install Watch 10.4.

I solved the problem by adding “step 2.”

Ok. So I chatted with support. I was told to shut the phone down first. Then the watch. Then power them back on and put them both on the charger and try again. For some reason that seemed to work and it is moving along now.

The solution that worked for was power off the watch.

press and hold the button below the crown wheel until the emergency screen appears and tap on the power switch symbol.

after the watch has powered down, press and hold the same button to reboot it.

10.4 should now load.

I was having the exact same problem, stuck at preparing. Decided to check the phone/watch connection by downloading a new watch face... successfully. This action also seemed to unstick the update process which began to progress again immediately afterward. Maybe a coincidence but it sure didn't seem like it.

I tried this and it worked on the third attempt!

A restart of the iPhone and Watch BEFORE you start the update seemed to help. Also - letting the watch run below 50% battery and then charging it also seemed to kick-start the update. It did sit at 60% 'preparing' for about an hour before it suddenly jumped to 90% and then installed. As others have said; make sure the iPhone and watch have a strong WiFi signal and don't watch it; it knows !

iPhone XR, Ultra 2

I tried updating for two days now, in the mean time barely being able to use my watch since the battery was draining. Deleting the download, shutting off both devices, nothing worked. Then I read here it helped for someone to link the watch to the iPhone, so I (randomly) updated my language preference to “match iPhone” and suddenly the preparing was finally moving up! So it seems to help if something re-establishes the connection between the two devices. Worth the try!

WORKED! Finally, after several unsuccessful attempts…

Thank you!

Step I did:

• on iPhone start app Watch
• go in Face gallery (central button at the bottom)
• download a new face and set it as current one

Progress update bar increase immediately!

AMAZING! 🤩

Same problem here as well: Update stopped while "preparing" about 3/4 of the way through. Tried some of the solutions described here with zero luck; however, it finally worked when I deleted the update as previously described by others, turned my iPhone (XS) and Apple Watch off/on, and then tried the update again. Success! Here's hoping this'll work for everyone else having this annoying problem.

I went into the airplane mode setting on my watch and turned on wifi.

This solved the stuck on preparing issue.

Iphone 14 and apple watch SE both running current updates.