Can't use the folder navigor, IDEA unresponsive

I'm not sure what this window is called:

http://puu.sh/sEmlH/3b15d421b9.jpg

Whenever I open this window, either from Open Project or Add Dependency or whatever, it never loads; and when I attempt the exit the window, IDEA becomes unresponsive. I have tried to update, uninstall, and reinstall IDEA to no luck.