My watch was not pairing with my phone. My phone showed that watchOS 26.5 needed to be installed. After two days of struggling and it saying 9+ hours left of installation, that part finally finished. Now it is stuck on preparing...
I can't get into my watch as it won't pair without updating. I can't get into any menu options in the watch app on my phone.
Did you already try to force restart your iPhone and your Apple Watch?
Force restart iPhone - Apple Support
To force restart your watch, press and hold the Digital Crown and the Side button together for about 10sec, until the Apple logo comes back again.
Before you do that, make sure that both devices can access your Wi-Fi and no VPN or firewall is blocking the contact to Apple servers.
I place my iPhone and the watch on their chargers, and put them right next to each other in short distance to my Wi-Fi router. That way the Wi-Fi connection is solid and fast for each device.
You can also update the watch directly, as explained in this article:
Update your Apple Watch - Apple Support
Did you already try to force restart your iPhone and your Apple Watch?
Force restart iPhone - Apple Support
To force restart your watch, press and hold the Digital Crown and the Side button together for about 10sec, until the Apple logo comes back again.
Before you do that, make sure that both devices can access your Wi-Fi and no VPN or firewall is blocking the contact to Apple servers.
I place my iPhone and the watch on their chargers, and put them right next to each other in short distance to my Wi-Fi router. That way the Wi-Fi connection is solid and fast for each device.
You can also update the watch directly, as explained in this article:
Update your Apple Watch - Apple Support
Apple Watch watchOS update stuck on preparing
