Mame has crc checks to make sure it uses the correct roms, The rom may work fine, But it does not mean it is correct for that emulator. I suggest you go fine the correct roms for that emulator. kof2k3nd is not even a proper dump, It has been hacked and protection removed. This is one of the reasons why there are differmt types of crc values. Again the bosses hack is just that, It only a hack (not offical) . If its not not showing the bosses then it means you do not have the correct rom set.