This type of situation occurs frequently whenever YouTube
temporarily shuts down some of its servers to update stuff.
If your YouTube seems slow or stuck, and you get strange
messages on your computer screen or advice from people
to update, change or install things:....DON'T. It's never good
to fool around with things you may not be comfortable with
or knowledgeable about -- such as java scripts, flash players,
firewall settings, antivirus utilities, pop-up blockers, registries,
or even different browsers. Absolutely none of those things
are going to help you, because your computer/YouTube was
working perfectly fine before, right?
The first and best option should ALWAYS be to try and work
with what you already have -- rather than disabling, erasing,
separating, uninstalling, altering, downloading, installing, or
changing things (which will make things worse for you).
The problem of slow or stuck downloading-buffering-playing
will often correct itself within a few hours or by the next day.
If it doesn't, then there may be a problem with your "cache",
especially if you get "java script" or "flash player" messages.
(That's why channel pages may sometimes appear normal,
but not regular video pages.)
Whenever YouTube seems stuck or displays strange things,
it is best to empty your cache of all "temporary internet files",
"cookies" and "history". Things are usually okay afterwards.
If you're not quite sure how to do this, or if you want several
other tips on how to make YouTube run faster (all without
having to change anything), then please click on my avatar
and email me. I will lead you through "cache" clearing and
all the other tips with easy and understandable "baby steps".
(Note: a big source of problems is Google Web Accelerator.
If you have it, uninstall/disable it no matter what -- even if it
contradicts my own advice).