Youtube videos were working fine two days ago but now they wont load. I get the perpetual loading circle. I can see the stills of the video if i scroll across the time bar, but the video will not play. Videos work fine in IE and Chrome. I've tried playing videos with and without flash player installed, but I get the same loading circle on black screen. I found the following post on these forums and I'm having the same exact problem EXCEPT downloading the Youtube All HTML5 add-on does not fix the problem. I've tried all the suggestions made in that thread. https://support.mozilla.org/en-US/questions/1047428 I've also tried doing a refresh of Firefox, and uninstalling/reinstalling Firefox, to no avail. Firefox 37, W7 x64