hi, you should update the adobe flash player plugin to the latest version which will not be blocked as it doesn't contain known security vulnerabilities: https://www.mozilla.org/plugincheck/

in-spite of downloading latest version of flash , the plugin is not installed

Hi, you are using an old version of Firefox. To update it, open the 3-bar menu > Help (question mark at bottom right) > About Firefox. Alternatively, you can press the Alt key to bring up the menu bar, then Help > About Firefox.

You are also using an old version of Shockwave Flash. Open the Add-ons Manager (Ctrl+Shift+A) > Plugins - 'Check to see if your plugins are up to date.'

If your question is resolved by this or another answer, please take a minute to let us know. Thank you.

Adobe Flash is notorious for not always removing old Flash Plugin DLL files as part of a Flash program update. Sometimes the user needs to uninstall Flash completely and get a clean start.

First, grab the Adobe uninstaller from here: http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html

Then download the latest Flash Plugin version from here: Select the Windows > Plugin-based browsers - the EXE version. https://www.adobe.com/products/flashplayer/distribution3.html

Run the Flash uninstaller program, then reboot your PC. Then install the Plugin version of Flash. So you'll have a clean installation of Flash for Firefox.

what does reboot your PC means, does it means I should close PC and start again?

Hi, in a word, yes!