Hi All, We've had an issue with a new sensor not getting to the warm up due to the dreaded "signal loss". We finally pulled the sensor after 3 hours of starting and stopping and trying again. I called Dexcom to get a replacement and was told that it probably happened with the new iphone software update (10.1 or 10.2). It was suggested that I uninstall the dexcom app, shut down the phone, open the phone again, reinstall the app and that would solve the problem. Has anyone had this issue recently? We'll try it again tonight...but it would be nice to know that software updates can play havoc with the Dexcom App! I'll keep you posted if this is, indeed, the fix! Of course, if our daughter would use both the phone and the dexcom receiver, we would have figured out that the sensor was okay...oh well!