Apple Watch Update

Ok, as a second check please use the guide Update your Apple Watch - Apple Support as a checklist. If you get a failure please post back and quote the exact failure message rather than an interpreted description.

In the worst case with continued failures you could try setting up a Genius Bar appointment for one to one assistance. Contact Support (link) if you want to go this route.

Your iPhone needs a WiFi connection to internet so it can download the update for the watch. Check your phone’s WiFi connectivity and make sure your WiFi has full internet access with reasonable speed (not always the case if you are on a public WiFi like a coffee store, and if it is the office WiFi you might be constrained by a firewall restriction)