Homebrew Pressing Play takes me back to Wii Menu - Project M 3.5

[YugamiSekai]

I have a 4GB SDHC Card, I use the homebrew method, and I started Project M in the Homebrew Channel. I pressed play and it took me back to the home menu. I used my other 2GB SD Card for the hackless method and all it said was "boot.elf not found (-1)". How do I fix this?

SIDENOTE: When I tried using Smash Stack with the 2GB SD Card, it gave me the same answer (boot.elf not found -1), but Smash Stack worked on my Wii U so I just used LetterBomb so I could use my 4GB SDHC Card.