make sure you have original game disc (whatever game that you have) in the bd drive
1. try using different payload (PL3 for example)
2. try using different BM (Gaia, MultiMan, Cover)
3. if still not working it could probably be due to problem with the backup game itself. sometimes the backup is corrupted, not properly ripped, missing some files, or the files are not in the appropriate folders.
Check the comments and description before downloading anything to see if it works and what configurations are needed to play the game. much like when you download movies, pc games or software from the net. its common sense.