clicked to change resource pack and closed

Put the summary of the bug you're having here

to change the resource pack
Describe what you thought should happen here

clicked on the pack to change to and it closed
Describe what happened here

Steps to Reproduce:
1. open minecraft 13w24b
2. go into options click resource packs
3. click the one to change to
4. it changes to default
5. click another pack to change to and it closes D: