Tethering won't work claiming data connection is unavailable

When I try to turn on tethering/mobile hot spot it gives me the system message "Unable to connect, data connection not available." However it worked in the past with this carrier/phone and the internet still works. I can browse the web on my phone fine. Things I tried so far: - restarting my phone - Taking it in and out of airplane mode - turning wifi off and on - turning on and off power saving - turning sync on and off - turning off high performance mode. - resetting all network settings