Well LT+ allows the 360 to pass the AP.2.5 checks so that it reads it as a bought game and not a burned game (simplest way i can explain it) with out it your system can read the disc as a copy (with older firmware) and cause it to fail reading the AP2.5 it was added in the kinect dashboard to stop (at least slow down) people copying games just do a search for Xbox 360 LT+ in google I bet thats the problem. LT+ is the newest version of firmware for your DVD drive you will need to know what model of DVD drive is in the 360 to get the version for it, are you the one that flashed the DVD drive? if not I would talk to the person that did it to see what version they used