Hi can anyone explain why my NeoGeo and CPS1 games will work in FBAXXX pro but that CPS2 games keep saying rom files missing and then starts to load the games and mostly freezes the xbox when the loading progress bar reaches the end.

I understand somewhat about gettting the correct files in each zipped game. What I dont fully understand is how to check and what to check for.

Emulator should tell you what files in the rom you are missing or have wrong named.
Second you should check .dat file that come with emulator (or generate them in emu) - there you find all roms sets with name of files (that should be inside the room, exact size , good CRC ......).

After that :
1. look on the web for correct roms
2. try rename them to proper names (in side the zip)

First option is better for you

Ps: check also pinned topic in this thread

Cool it worked I got a whole new set of CPS2 roms which included all the XOR files which is better for backward compatibility of emulators. Hey Great full for your help thank you.