New transmitter and new sensor out of range?

I have had the Dexcom for a few years. Over a year ago I got the G4. I had to get a new transmitter due to "low battery". I just put a new sensor in this morning with the new transmitter and it has been saying "Out of range." I never got the calibration message and it has been out of range the whole time despite being with me. Has anyone had this happen? What do you do in this situation?