UPDATE.... just figured my situation out...
you need to make sure the TU is compatible with the "media id" of your game... just copy the default.xex of the game to your PC (or set up an SMB share in FSD) and then load the file in abgx... you need to look at the Media ID value (end of the string) and make sure the TU media id matches... use xboxmodder or other site for the TU updates.... and then put it in the normal spot (cache directory or look into the FSD TU manager process) and you should be good to go...
UNLESS.... the media id value in abgx is all zeros..... this appears to be my issue with most of my games... for each game that wont load with a TU applied my default.xex's all have 000000 values in abgx.... the fix is to get an original default.xex for each game and overwrite the bad default.xex... apparently its due to a bad patch job in xexmenu... if anyone has a faster way for me to fix this issue please let me know... i have ALOT of games to fix....