"Flash Player" messages, and people are telling you to get
or install something, please...DON'T TOUCH A THING. You
will get nowhere fooling around with "Java", "Flash", or even
different web browsers.
None of those things will help you, because your computer
and YouTube were working perfectly fine a while ago, right?
The first rule-of-thumb and best option should ALWAYS be:
don't disable, erase, uninstall, switch, download, alter, add,
change or install anything. That'll only make matters worse.
are fine. Nothing about watching YouTube videos has really
changed in the past couple of years. If anything, the newer
Flash Players have been known to give many YouTubers a
lot of trouble, especially all 5 variations of version 10. (Why
in the world is there a 10.0.525, 10.1.218, 10.2.26, 10.2.54
and 10.12.36? The only thing that most upgrades are good
for is their potential to create all kinds of software conflicts).
Your problem may fix itself within a couple hours, or by the
next day, because YouTube often "shuts down" a bunch of
their own servers every single day without warning anybody,
in order to update all kinds of stuff. During those occasions,
it is actually YouTube's data transmissions of "Java" and/or
"Flash" that are poor -- not yours.
If the following day your YouTube is still stuck and showing
it is possible that your subdirectories of "temporary internet
files" and memory (many times called "cache") are entirely
maxxed out and cannot take anymore, the end result being
that YouTube videos cannot even make it onto your screen.
"Temporary internet files" are tiny bits of webpages that get
permanently put on your computer's hard-drive. They'll stay
there forever and ever, gradually plugging up your computer
much like hair slowly clogs a sink drain, until you get rid of
them. The solution to that is to clear your "cache" of all the
"TIFs" as well as your "cookies" and "history". Then reboot.
Note 1: a very odd fix that once worked for me was altering
the URL from "www.youtube.com" to simply "youtube.com"
(or you could even try "ca.youtube.com").