Apple Watch won’t update to 3.2.3 unable to install update

Hi

Follow these steps, trying to update your Apple Watch again after each, before moving on to the next if necessary:

Update your iPhone to the latest version of iOS (start by making a backup):

• Update the iOS software on your iPhone, iPad, or iPod touch - Apple Support

On your iPhone, in the Watch app, go to: My Watch > General > Usage > Software Update - delete any update file, if one is shown.

Delete any beta profiles that may be installed for your iPhone and/or Apple Watch and then restart both devices after doing so.

Restart both your iPhone and your Apple Watch (normally):

• Close the Watch app on your iPhone:
  • Double-click the Home button, then swipe up on the Watch app preview to close it.
• Turn both devices off together, then restart your iPhone first;
  • Restart your iPhone, iPad, or iPod touch - Apple Support
  • Restart your Apple Watch - Apple Support

Unpair and re-pair your Apple Watch (which updates watchOS as part of the process):

• The Watch app on your iPhone takes a backup of your watch when unpairing via the app. Choose to Restore from Backup when offered the option during set up. Most data and settings will be restored, with some exceptions (eg Apple Pay cards, passcode).
• Unpair your Apple Watch and iPhone - Apple Support
• Set up your Apple Watch - Apple Support

More information:

Update the software on your Apple Watch - Apple Support