I have Elisa mobile provider. Recently, I obtained HTC One device.
today, I came to Latvia and tried to connect to any local operator. On every try I got a message “Your SIM card does not allow a connection to this network”.
I rebooted phone several times, ejected and inserted sim card also. Even tried to shake the device. Nothing helped.
Google helped again.
1. Open the phone dialer
2. Enter: *#*#4636#*#* (Once entered, you will be taken directly to a “Testing” page) [4636 spells INFO]
3. Tap Phone Information
4. Scroll to the bottom of the screen and you should see a button that says radio off. Hit this button and when it reads radio on Hit it again to turn the radio back on. <-- (Not a Typo)