Changing resource packs crash the game

Put the summary of the bug you're having here

What I expected to happen was...:
Changing the resource packs would simply change the resource packs

What actually happened was...:
The moment I changed resorce packs the game crashed

Steps to Reproduce:
1. Make or get a resource pack
2.Go to options and then resource packs
3.Select a resource pack,then start up a world