It works for me using Windows 2008 and Firefox 38.0 (I'm at work, don't judge! ☺) With so many tweaks and fixes being implemented, it's very possible the issue you're experiencing is limited to your session state and cache. Can you please follow Steps 1-3
of our Solving Technical Issues wiki page (temporarily disable all
browser add-ons and extensions, temporarily pause any anti-virus, and
try switching browsers (for Chrome/Firefox specific issues) ) to see if
one of those components is causing the problem. If one of those does fix the issue, just let us know :) If none of that resolves the issue, please follow Step 4 , so that we can have this information to further assist.