I switched from AT&T from whom I bought my Galaxy SIII to T-Mobile by having a T-Mobile SIM card installed into my unlocked phone.
Everything works well EXCEPT the phone's own ability to set up the "Tethering and Wi-Fi Hotspot" function. When I try to enable it I get an error message "Mobile Data is not available or invalid SIM." I went back to T-Mobile and had the SIM chip changed and the Wi-Fi Hotspot function still doesn't work. I get the same error message. I spoke to T-Mobile, Samsung and AT&T's tech support departments. I get different answers, none of which correct the problem.
Any suggestions would be most welcome.
Everything works well EXCEPT the phone's own ability to set up the "Tethering and Wi-Fi Hotspot" function. When I try to enable it I get an error message "Mobile Data is not available or invalid SIM." I went back to T-Mobile and had the SIM chip changed and the Wi-Fi Hotspot function still doesn't work. I get the same error message. I spoke to T-Mobile, Samsung and AT&T's tech support departments. I get different answers, none of which correct the problem.
Any suggestions would be most welcome.