Heyo,
I've had this problem for a few days now. Whenever I attempt to view a YouTube video, it always either gets stuck on the loading of it or I get the message "This video is currently unavaliable" / "A problem has occured, please try again later". I've tried updating my Flash and Java. I've tried Opera, Chrome and Firefox. I've tried deleting the caches, doing fresh installs of them, updating my antivirus, running with no addons - you name it. All videos on other sites work, it's only those on YouTube or those embed from YouTube. I've also tried running with HTML5 instead of Flash, and it did work, but only for one measly video. My girlfriend runs YouTube on her computer without any issue.
Do you guys have any idea as to what might be the problem? This is getting frustrating. Thanks. <3