my moto g 2nd gen. was fine for 3 months after I bought it Unlocked from B.Buy. then it started to lose connection with the micro sd card. I have been using the same sd card from the beginning.
it started to give error messages about the sd card being removed, has an error, need to be formatted.....etc.
I tried all the solutions proposed by the motorola service people on the phone and online. removing and re-installind sd card, formatting sd card, replacing sd card, formating phone,......etc. it all came down to the same results the sd card may or may not be connected to by the phone to be declared at error or removed soon.
finaly the support team suggested replacing the phone for me. at the moment I'm waiting for the new replacement phone. and we will see what happens from then!!!