Tubal Cain

I'm playing 1.09, and when I replace the files in the asset folder with those in the zipped file, my game crashes on launch. I get the launcher, but when I press the "play" button, the screen pops up, but crashes before the screen does anything but be white/blank. I have tried installing twice. Any ideas why this might be happening? EDIT: Got it working. I must have been screwing up with my unpacking, because I just replaced each file individually and it's working!