I have another one just first try Mister Cerb solution.
If don´t work maybe your problem is the game...
I will explain that, Guilty Gera XX Reloaded it´s a XBOX "1" game and for that works you have the update for compability for xbox games!!!, look in memory go to system and see there if have that data, if not try in contact whif xbox support to how download
it (in disc normaly the system detects and sugest the start of the tool "emulates" Xbox, in GOD (games on demand) in auto mode, i don´t know how works in GOD (because all Xbox "1" games it´s a IP blocked for another regions).
If after that don´t work you have a confront a rare compability problem "Slims" models have whif xbox "1" games, and you have to enter in contact of the publisher of game (ARK SYSTEM Works) by their site or support and comunicate the problem and all solutions
you have tried and require refund (or if they have a good spirit if they can send a download code for Guilty Gear XX Accent Core, that´s a arcade game, but that´s is the most recent version of the same game; Guilty Gear XX; in Xbox live or try their solutions).
I hope i help you and forgive (again my bad english, and the lazy of answer because it´s much versions of this game and i have to make a search to locate what version you have talk about, and i presume is reloaded, only exists in xbox "1" and not Accent
Core relased in arcade XBLA in 2012) it´s self learnerd.