Could it be that you are using a PAL version of your iso instead of an NTSC version? You cannot mod the PAL version of the game. You could always try using the injection method, which I think is better in general unless you are constantly modding the game with new mods. Here's a guide on doing that to play Project M on Dolphin via injection: http://smashboards.com/threads/project-m-dolphin-online-via-netplay-full-setup-optimization-guide.346700/page-3#post-16610981
[color=green]Windows 7 x64 / i5 4690k @ 3.5 GHz / GTX 970 / 8GB RAM[/color]