Usually a .zip file (like umk3.zip ) containing the program code.
The "463" in your error often refers to a specific build or revision number within a MAME "dat" file. If your emulator version expects a certain file (like ultimate.u64 ) and it isn't in your ROM folder, the game will fail to launch. Why UMK3 is Considered "Better" 463 mk3 ultimateu64 not found better
Find the ultimate.u64 file and place it in the /umk3/ folder. Usually a
Arcade games like Ultimate Mortal Kombat 3 are complex. Unlike simple console ROMs, arcade sets often consist of multiple files: 463 mk3 ultimateu64 not found better
Use a ROM manager to verify your set against your MAME version. Upload the kernal.rom and basic.rom via the Ultimate menu.