Several UI files were updated in today's patch which made mostly all of the interfaces unusable. (sad panda).
Edit: All UI's have been updated for the 3/25/15 patch day. Enjoy!
A minor update to the Default Old interface today, you do not need to update it as it was just 1 word in a description that was changed.
A general update to fix various issues was patched today, thankfully no UI patches are needed, yay!