Can't send or reply to messages.

Yep - having exactly the same issue!

 

I'm not having this issue but just as a thought, does everything look alright in your iMessage settings? (Logged in with your Apple ID under Settings -> Messages)

 

It keeps putting the 44 country code in when I try to send an iMessage. Anyone else having that problem

 

I had the same issue. I believe it was because I have two-factor authentication on. If you do as well, go to appleid.apple.com and go to password and security. Once there, create a single app password and just name it something like messages. Then restart your apple watch. The watch will tell you to reenter your icloud password on your phone. A message will pop up on your phone asking for you to enter your password for messages. Just enter the single app password you created instead of your Apple ID password. This resolved my issue.

 

I've had this issue of messages sending but saying they've failed, and I don't have 2 factor set up. It doesn't happen all the time.

I've also had an issue where I switched the watch off, and when I switched it back on, it brought in messages I'd already read, and put them below newer messages. The time stamps correctly identify them as older messages, but they're at the bottom of the list.

I'm guessing these are just software bugs.

 

I have 2 factor on as well, and this worked! Thanks!