Per the title. The issue came up after a Flash update. It seems to work fine in Firefox and Chrome, but when I try to, let's say, watch a YouTube video in Firefox, it won't work. It's not confined to YouTube, either: the same thing happens with Hulu as well as The Nostalgia Critic's website, whose videos are hosted by Blip.tv. I'm pretty sure that the problem isn't JavaScript or another type of script, because JS appears to work fine - the dropdown list on YouTube's search bar functions how it's supposed to and Wikia's main page loads correctly, and these are functions which I know run off of JS. The same thing holds true for Sliverlight scripts and all of my other script plugins except for Flash. I've tried clearing my cache and starting a new Firefox profile. I even reinstalled Firefox, but I kept all of my profiles when I did so, so I'm inclined to believe that if indeed it is a problem with Firefox and not with the Flash plugin, then it's a problem with one of the profiles.