I have the latest Flash player (and, indeed, did follow the link and upgrade it just to make sure). However, this kept occurring for a number of YouTube videoes I then tried to watch as a test.
A bit of investigation indicated a huge range of suggestions for how to fix this - everything from people claiming it is a bug with YouTube and "YouTube Engineers are working on it" through to those advising turning off various bits of your Internet Explorer security settings (such as any "Add blockers" etc) and deleting temporary internet files and cookies.
Given that these fixes didn't work for me - and I don't want to leave my browser in an unsafe state with popups etc, anyway - I changed all these settings back to their usual state.
SOLUTION (Well, almost!):
I did, however, come up with a way to watch the video.
Now, to be honest, I haven't actually fixed the problem - when I go to the original URL I get the same error message still - but, on the positive side, I can watch the YouTube video (which, after all was the point). To do this, you just need to modify the URL you are using slightly.
In this particular case (as embarrassing as this may be - I didn't choose this video), my friend wanted me to view the link:
This didn't (and still doesn't at the moment of writing this) work for me. However, if you modify the link to:
- remove the words "watch?"
- replace "=" with "/"
I obtain a new URL that does work:
So, the good news is this worked. The bad news is that had I known what the link was for I wouldn't have wasted the time :-) Ok - so maybe it isn't that bad?!?
Anyway, music taste aside, the good news is that this works on all the YouTube files I've tried so far. They're all giving me this same error message but, if I really wanted to, I could watch them by changing the URL manually...
So... it isn't a long term fix - but maybe this is a good start for others if the problem is with something at YouTube's end, or if you're just in a real hurry to watch that link you've been sent and don't wanna spend days re-installing Adobe products and Virus scanners!!!