Problem
Flash player is not working in browser (Chromium) on Linux Debian.
Solution
First of all, you have to edit this file
/etc/apt/sources.list
and add the following line
deb ftp://ftp.debian.org/debian stable main contrib non-free
Next open terminal and type the following command
$ sudo apt-get update
or
# apt-get update
Then run this
$ sudo apt-get install flashplugin-nonfree
or
# apt-get install flashplugin-nonfree
and restart your browser.