Don't make changes on weekends.
I tried teturning car to stock one Friday night to download new tunes and add, Something went wrong, everything failed. Nothing would wrk. Had to wait until MMonday morning when SCT had tech support on duty, once they came to work, we got everything right. Had to wipe the device of everything, then re format it. Glad my car was in my garage.
That is the only time i have had any problems, like said above, make sure you update the device and return PCM to stock before putting any tunes on it.
2014 GT500 DIB, SVT PKG, leather Recaros, Factory Nav, UPR shorty antenna, Redline hood struts ---Sold---2011 Mustang GT Premium, Kona Blue, Automatic, comfort package, electronics package, security package, backup cam, HID's , 19" Black GT500 Wheels, Steeda CAI ,Borla over axle pipes and S-type A/B, black UPR shorty antenna, JBA Longtubes JBA Catted X-Pipe,, Dyno tuned by Brenspeed... An Armed Society is a Polite Society..