Recently I formatted my pc and after reinstalling windows I immediately downloaded Firefox and synced my profile. For some reason, videos on some (most websites) are not working at all. They just dont play, and these are websites that I used just last week on Firefox, and that I've tested on other browsers and work just fine. I've tried troubleshooting mode, new profile, deleting cache, etc, and nothing has worked. On some websites, I dont even see the player, its just blank, and in others I see the player but no playback (doesnt even seem to buffer). YouTube works just fine strangely enough.