@ gonzo
so info regarding dlc being played from external is incorrect at link below (op has posted multiple threads instead of 1 large one),or can dlc only be played from external hdd if it doesn't exceed a certain amount of gb there by making 360 think it was an mu,i was under impression an external hdd wasn't capable of using dlc & instead required internal or mu
http://www.realmodscene.com/index.php?/topic/4279-using-dvd-extract-for-multi-disc-games-quick-question-i-think/
@ op
you need to link xbox to unity & possibly enable the auto retrieve thingy,,me i just hit scan manually since i don't have it set to auto,any covers missing i use web browser to install,i've only used push to xbox once & that was under the old site
install missing covers manually by using web browser by logging into 360 using 360 ip address then type 360 address into web browser,should work if 360 is set up correctly