WatchOS 27 Update Issue

Try this in your watch (not on the phone): go to Settings -> General -> Software Updates -> Install. It might require that you confirm the update on the phone and place the watch on the charger.

There seems to be a glitch in iOS27 that prevents the installation from being started on the phone.

I hope this helps.

My install stopped stopped after "preparing update" completed. I did as suggested above on the watch (not on the phone): go to Settings -> General -> Software Updates -> Install). The install started immediately. Thank you!

There is no glitch with the watchOS 27 being started on the phone. The issue is that many folks seem to misunderstand that when starting the download from the Watch app on an iPhone, you must enter your passcode on the watch to proceed with the download and installation.

The watch has to be on its charging puck for watchOS to be installed.

Same issue here with a brand new Ultra 4.

• On iPhone 17Pro Watch app stalls on Preparing.
• Then rebooted Ultra 4 and iPhone and used on Ultra: Setting/General/Software Update and update worked fine.

Thanks for the advise

**Update**

I updated my phone to the iOS 27. I unpaired the watch and iPhone. I put the watch on the charger and made sure my phone was connected to both wifi and bluetooth. I restarted the process of pairing and updating the watch OS. The process took about an hour, but it worked.

We tested the heck out of watchOS 27 in beta. I had no issues installing it!

The issue is that many folks seem to misunderstand that when starting the download from the Watch app on an iPhone, you must enter your passcode on the watch itself to proceed with the download and installation.

The watch has to be on its charging puck for watchOS to be installed.

If watchOS 27 has downloaded but won’t install, first make sure the Apple Watch is on its charger, above 50% battery, connected to Wi-Fi, and close to the paired iPhone.

Then try:

• Open the Watch app > General > Software Update and check again.
• Restart both the iPhone and Apple Watch.
• If the update is stuck, delete the downloaded update from the Watch app if the option appears, then download it again.
• Make sure the iPhone itself is fully updated.
• Temporarily disable VPN or network-filtering services.

If there is still no Install option, it may be a temporary verification or update-server issue.

More Apple Watch and iPhone troubleshooting guides: https://nexploreinfo.com/how-to-download-and-install-ios-27/

I had the same, until I went into my watch (series 9) and saw it said verifying. When I placed my watch onto the charger, after a little while it started installing.

Had the same problem. Going to settings on the watch and hit install there fixed the problem

El Chavo wrote:

So, the issue has nothing to do with "a glitch in watchOS 27"!

The issue is that folks have not updated their devices to the most recent previous OS before attempting to upgrade to the new OS!

Apple software usually requires that a device is up-to-date, before any attempt to move on to an upgrade of a new OS. In this case, an Watch needs to be updated to 20.6 before upgrading an iPhone to iOS 27 and a watch to watchOS 27.

Yes, a careful reading of Apple's instructions does indicate that the order indicated by El Chavo has to be followed. That said, it seems that Apple's process maybe should be more forgiving of being behind on the latest version on the watch. For most Apple devices, one can skip over multiple intermediate updates while updating to the latest. However, there are apparently enough fundamental changes in moving to OS 27 for all Apple devices that Apple's documented step by step process needs to be adhered to, as indicated by EL Chavo: both the watch and iPhone need to be on the latest version before first the iPhone is updated to 27 followed by the watch to 27.

bcgav wrote:

Not just updating an Apple Watch to WatchOS 27, updating an Apple Watch that is on WatchOS 26 that is not supported in WatchOS 27 and had a pending WatchOS 26 update downloaded.

Exactly. The latest version of WatchOS 26 has to be downloaded AND INSTALLED before the update to WatchOS27 should be executed. The iPhone also has to be on iOS 27. This is all explained in Apple's guidance.

For those having this issue updating watchOS 26 on iOS 27, see this thread for a solution:

Apple watches cannot be updated to watchO… - Apple Community

@El Chavo - FYI apparently there is a bug where a watch that has downloaded but hasn't yet installed a pending watchOS 26 update that is paired to an iPhone that gets upgraded to iOS 27 prior to the update, the watch ends up getting stuck where the update continues to fail.

If you will recall, Apple released public announcements that were carried in most tech mags at the release of 26.6, that OS 26.6 prepared Apple devices for the upgrade to OS 27.

https://duckduckgo.com/?q=watchOS+26.6+prepares+Apple+hardware+for+OS+27&t=brave&ia=web

I am setting up a brand new iwatch 11. It wouldn’t install until I updated my iPhone 13 mini to iOS 27. That worked. The Iwatch 11 has been “installing” now for a day, with nothing showing in the watch screen except “46mm aluminium case”. Obviously I can’t go to the watch settings. Any ideas? Garmin perhaps?

I’m currently experiencing the same issue. I have a brand new watch 10 series and I’ve tried installing with no success and disconnecting and resetting several times. I’ve also updated my phone to the latest OS.