It isn't the stages becauese i dn't have any custom stages loaded... and can you tell me what SC_selmap.pac and Common5.pac are?

So i just started hacking and i uploaded some different textures for peach onto my sd card... and everything works fine until i get to the stage selection screen... it freezes every time i go to pick a stage, I have tried all the costumes and they all do the same thing (cause the freeze.) I have the files named correctly and placed in the right folders but whenever i attempt to pick a stage with peach, it freezes...

I have gecko, and riivolution downloaded and it happens with both of them... can someone help me, is there something i am missing and just havent downloaded yet?