I rooted my galaxy s3 i9300 tot 4.4 kit kat , but had a few problems with apps crashing. so I downloaded and installed the original firmware 4.3 and now I have no internet connection and no network. it keeps telling me emergency calls only or not registered on network. im from south Africa. any help on how to fix this problem will be appreciated. I have just downloaded 4.1.2 firmware and the modem file but don't want to try it if its not gonna work. please im desperate.