My youtube videos aren't loading.?

When I get to a video (any video on youtube) the video player just stays a black screen (not even the play on) or loads the play on the the timeline but never loads. None of the Youtube downloaders work, something about "unable to parse" or "QueryStatus 200" and whatnot. I'm pretty good with computers but this is just bugging me and I can't figure it out. It has worked on my computer before. I have the latest Flashplayer update. Any help guys?