REG99 "Unable to connect"

Check the channel your wifi router uses---I think it has to be 2,6 or 11. Don't quote me on that though. I use 6 and it works fine. I haven't been terribly impressed by the wifi calling on my phone. Resetting the router can help, assuming you've had success at some point getting through. It could be relating to other settings on your router--check security/firewall issues.