Is this for Mame? By not working what do you mean? Do you get an error or does it just go black and return to LaunchBox? Did you test the games in the emulator to make sure they work? If this is Mame did you use the Mame full set importer and do you have a full mame romset?
Right click the game, edit it and in the additional apps tab select the one you want as the default.
There are several version as games for many platforms have different versions for different regions. It can be any number of reasons why. Bad roms, missing support files, and a number of other reasons.