Step 1.Make sure your running the latest 1.18 offical firmware.
Step 2.If step 1 fails then take the files off your card put them on your pc format your memory card then add the files back.
Step 3. Find a different source to get the game from,if the game has multiple rom groups then try a different release.
Step 4.If none of that crap works and you still want to play the game then I guess go buy it if you can't make it work.
Step 5. If your not using 1.18 firmware and posted this i'll smack you
Step 6. Your Welcome.....