I have a 32x32 texturepack its pre-unstitched so i converted it with TextureEnder, and launched snapshot,and 1st issue: the grey frame didnt selected it ( i know this issue has MANY duplicates) and didn't crashed like in MC-17839, but look at the screenshots....weird
Can you please redownload the snapshot version 13w24b and/or try with 13w25a: In MC-18146 did that help.