Im having the same problem. Says "roaming indicator off". When i try to send a text through my stock messaging app, it says "no usim". In my setting, my mobile networks menu is locked. I cant select it at all. However, i can text through the hangouts app and everything else works on my phone. I can call, use internet even while im not connected to wifi. Has anyone found a way to fix the problem? The guy at the sprint store just said "ive never seen anything like this".