Particles Crash in Beta?

I’m trying to make some simple particles, but I’m getting rather annoyed.
I’m running Gmod Beta at the moment with -tools. Whenever I put any .pcf files in the directory besides that mutant.pcf, the game starts up but crashes once it reaches the inital loading screen. Well, it doesn’t even crash, it just closes. It doesn’t matter whether I have -tools on, it’s just whether the particles are in there. I am absolutely sure this is the problem since I’ve explicitly tested with and without the particles. Thoughts?

Oh, and it works if I put the .pcfs in the particle folder after loading, but then they refuse to load into the game.