Hello,

1. Go to about:config search for plugin.default.state and change its value to:
   • 0 - never activate.
   • 1 - ask to activate.
   • 2 - always activate.

• about:config

If you want to do this for individual web sites;

Go to the web page. After the page is loading, mouse to the address bar and LEFT click the icon. A window for displaying site information should come up. Select More Information. Then Permissions. Go thru the list. You can manually change the settings as you wish.

Thank you very much!

It will be better If I can mass change the option in screen 'about:addons'

I guess that "plugin.default.state " is only work while the add-on installation process? after the add-on installed, it cannot reset all add-on by the value default

You can set the default behavior on the "Firefox/Tools > Add-ons > Plugins" page.

• https://support.mozilla.org/kb/why-do-i-have-click-activate-plugins

how can i roll this solution for a corporate enviourment

Firefox plugins have an option "Ask to Activate"/"Always Activate"/"Never Activate", now I have to choose it one by one, how can I set a default to all plugins and change them to always activate in a corporate enviourment,

Thanks for your help!

You can use a mozilla.cfg file in the Firefox program folder to lock prefs or specify new (default) values.

Place a local-settings.js file in the defaults\pref folder where also the channel-prefs.js file is located to specify using mozilla.cfg.

pref("general.config.filename", "mozilla.cfg");

These functions can be used in the mozilla.cfg file:

defaultPref();	// set new default value
pref();		// set pref, but allow changes in current session
lockPref();	// lock pref, disallow changes

See:

• http://kb.mozillazine.org/Locking_preferences

• http://mike.kaply.com/2012/03/16/customizing-firefox-autoconfig-files/
• http://mike.kaply.com/2014/01/08/can-firefox-do-this/