cannot update apple watch to watch os 4.x
I'm currently using iPhone 6s with 11.1.1 and apple watch 1 with watch os 4.0
I saw a red mark in watch app so I click software update but it was loading very long and finally a message "could not connect to apple watch". I tried to restart both iPhone and apple watch but same error message.
I tried follow Update your Apple Watch - Apple Support but also the same error.