I own Apple Watch Series 1 and I tried all the above solutions for 2 days and nothing worked for me. Below are the steps that worked for me, I hope it helps someone! Please note: My problem started when I Erased all my settings and contents on the Apple watch, when I started to connect my watch to new phone then this problem arisen. Made sure my Iphone is up to date with all the latest software updates Sign out of the ICloud account on your Iphone Hard refresh the Iphone -- Pressing Volume UP button once, down button once and holding the power button until the phone is turned off. Delete the Watch app from Iphone Hard Refresh the Iphone again Hard refresh the Watch Install the Watch app again Then tried to pair the watch with the Phone worked, it started downloading new update. Hope this helps someone! Good Luck