INSTALL OR UPGRADE FLASH PLAYER ON LINUX

Download FlashPlayer from below URL 

http://get.adobe.com/flashplayer

install_flash_player_xx_linux_xxx.tar.gz

tar -xzvf  install_flash_player_xx_linux_xxx.tar.gz

mkdir  ~/.mozila/plugins
or 
sudo ~/.mozila/plugins
or 
search the path of mozila as it is hidden folder as .mozila

mv libflashplayer.so ~/.mozila/plugins


OR
mv libflashplayer.so /usr/lib/mozilla/plugins/

restart firefox and check addons