I watch

[HP4]

I have recently upgraded and now my watch has stopped working in line with my phone. It says no sim and no connection?. 

How do I my watch to pair again with my phone?

Thanks

[pgn]

Is it via Bluetooth only, or with its own cellular e-sim, @HP4?

The guide for iWatch pairing to iPhone and cellular config is here: Activate Apple Watch Guide 

Good luck!