game crashes when changing resource packs

Put the summary of the bug you're having here

What I expected to happen was...:
I expected to change the resource pack to a diffrent one from default

What actually happened was...:
my game crashed

Steps to Reproduce:
1. log on to 13w24b
2. go into options, teaxture packs
3. select thejohn smith legacy resource pack
4. the game crashes

also when I log back on, the words are all jumbled up to the point whare you can't read them. when I try to switch back to the default, it crashes again