Windows Media or other plugins stopped working after Firefox update
Note: This article only applies to Windows.
Note: This article doesn't apply to your version of Firefox.
Some plugins that are no longer maintained, like the Windows Media plugin, have their files installed in a place that Firefox no longer supports. This causes the plugin to stop working. We'll explain how to make these plugins work again.
Change a Firefox setting to turn these plugins back on
In the address bar, type about:config and press EnterReturn.
The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise!I accept the risk! to continue to the about:config page.
Search for plugins.load_appdir_plugins
Double-click plugins.load_appdir_plugins to change its value to true.
Click the menu button
and then click ExitQuit
When you restart Firefox the plugins will be enabled.