Work gave me an AT&T iphone 6. My personal phone is an ATT iphone 4S with unlimited data. I thought I would be clever and switch the sims and back up and restore. This is what I did: 1. backed up the 6 on one computer and backed up the 4S on another. 2. cut the sim of the 4S with a quality sim cutter. 3. reset all data/erased the iphone 6 4. plugged the 6 into the computer with the 4S backup, performed a restore from backup from the 4S backup. This seemed to work fine. Except I have no data now on the 6. apps work ok on wifi, but things like mail give me this message: "you are not subscribed to a cellular data service" The top of the phone display says "4G". LTE is enabled in the settings. I tried a hard reset. no dice. tried toggling LTE on and off. Data on and off. airplane mode on and off. Calls work fine. Is a cut 4s sim not compatible with the 6? Anything else I should try before I give up on this and put this sim back in the 4s?