After a software update, my S7 will not work with my SIM card. What can I do?

[Android Central Question]

I purchased an unlocked ATT Galaxy S7 and a Consumer Cellular SIM card. It worked for a while, but then didn't after a software update.

 

[Rukbat]

Contact Consumer Cellular. The update shouldn't have had any effect, whether the phone is unlocked or not shouldn't (CC uses AT&T towers, so that's the SIM they should have sent you), so everything should be good at your end. (The problem is that - unless you manually updated the phone - Samsung sent the update, so Samsung and CC can point fingers at each other.) If you manually updated the phone, you may have used the wrong file - in which case, using the right file may fix things, or you may have to back up anything that's not backed up and reflash the ROM.