I got this message when i tried playinga video on youtube ....
It is actually a problem at YouTube. They have issued the following statement:
"Wednesday, October 24, 2007
Users with ad-blocking software enabled may not be able to see videos due to a conflict with our flash detection code and may see this error. Our engineers are still working on resolving this issue but it is expected to be fixed soon. If you are unable to see any videos because of this issue, you may want to try temporarily disabling ad-blocking in your browser or security software. Thanks for your patience."
Thanks to yahoo answers