"I am an atheist, out and out. It took me a long time to say it. I've been an atheist for years and years, but somehow I felt it was intellectually unrespectable to say one was an atheist, because it assumed knowledge that one didn't have. Somehow it was better to say one was a humanist or an agnostic. I finally decided that I'm a creature of emotion as well as of reason. Emotionally I am an atheist. I don't have the evidence to prove that God doesn't exist, but I so strongly suspect he doesn't that I don't want to waste my time." – ISAAC ASIMOV
Quick solution: WAIT (1-2 hours) and manually register the SIM with the Mobile Network (AT&T, Viettel, olleh, etc.) in Settings section. I had this problem when traveling from Vietnam to Korea. My SIMs worked fine in Vietnam, I had 2 of them and both didn’t work when I brought them to Korea, 1 SIM was… Continue reading SIM not provisioned when roaming