Go to

menu > Preferences > Software & Updates > Peppermint Software (tab)

and make sure all boxes are ticked except "Source" .. in particular, amke sure the "(multiverse)" box is ticked.

Click "Close"

Now open a terminal and run:

then

Did it install this time ?

OK it installed.
but yet youtube runs just the same.

I ran the commands from the beginning of the thread and got this:

yishay@yishay-Inspiron-1012 ~ $ locate libflashplayer.so
yishay@yishay-Inspiron-1012 ~ $ dpkg -l | grep flash
ii flashplugin-installer 11.2.202.233ubuntu2 Adobe Flash Player plugin installer
yishay@yishay-Inspiron-1012 ~ $



sure it's a flash problem? I mean, flash games work just fine..

thanks a lot.

Have you run a full system update yet ?

yep

I take it you've ruled out a plugin, by disabling them all ?

I take it you've also tried clearing the cache/cookies/site data/etc ?

Try temporarily disabling cookies:
https://support.google.com/accounts/answer/61416?hl=en
then restarting chrome/chromium

Might want to do a wash, rinse, and restyle of your chrome/chromium install. I've had to do this in the past.

Sometimes, nothing else works...