You have lost data connectivity because you left your home network with data roaming turned off I get a "you have lost data connectivity because you left your home network with data roaming turned off " message whenever I turn on my 4G connection. The problem is my sim card if from the same country I live in now. This problem somehow remained since I moved, from my old sim card, and now I can't seem to get rid of it. I also see an R next to the connection indicator. 

My phone is a Huawei Ascend Mate 7. Anyone have any idea on how to solve this?
I solved this by going into settings, SIM and network, and selecting SIM 1 (the phone carrier SIM in my case Giffgaff). This showed me another setting for mobile data which was switched off. Once I switched it on it found a nearby 4g source.