((Windows 7, 64 bit, Internet Explorer, latest version flash and one before latest, I (tried both)) System had a virus, ran rkill and combo fix in safe mode, virus removed, other malware manually removed. Upon testing the machine, visited youtube. I have not been able to get past the error "An Error Has Occured Learn more." the peculiar thing (after clearing cache, cookies, resetting IE, etc) is even thoguh I change the settings within youtube to not play HD, it seemingly attempts to quickly run all as HD which sort of causes the video buffering and playback to sort of loopback a time or two immediately after beginning the first few seconds of the video at which time the screen goes like a dark static fuzz with that error message displayed. Here are a few of the thing I will try tomorrow, including editing the registry ... and oh yes, most mysterious thing was that I am pretty sure I got it to run once briefly by disabling all addons but could not recreate the fix post full installation of latest version of new flash ... like it would play only during the installation of flash, plays fine in other browsers ...
Here is what I found. I particularly like the one about editign the registry within Compatability flags within local machine/software/windows/activex, etc, etc
http://helpx.adobe.com/flash-player/kb/movies-dont-appear-browser-flas h.html
http://download.cnet.com/ActiveX-Diagnostics/3000-2247_4-13546.html
clear cache?
WAIT … did I get it to run in IE? Yes! Was it chrome?
http://www.youtube.com/watch?v=n_kDQPMT5ls
http://forums.adobe.com/message/4483392
http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows. html
http://www.youtube.com/watch?v=H1MvpKqgXJg
delete cookies? Clear internet cache? Winsoc reset?
F5 a bunch of times?