Hello zioerr, see if the next is helpful : http://kb.mozillazine.org/Determining_plugin_directory_on_Linux

thank you

See also:

• https://developer.mozilla.org/en/Gecko_Plugin_API_Reference/Plug-in_Basics#How_Gecko_Finds_Plug-ins
• https://developer.mozilla.org/en/Gecko_Plugin_API_Reference/Plug-in_Development_Overview#Installing_Plug-ins

Thanks. It seems like it all depends on how Firefox was built.

Seems like the binaries (23.0.1) for Linux found on the mozilla.org website don't search for plugins under ~/.mozilla/plugins or the path defined by the env MOZ_PLUGIN_PATH.

I decided to build Firefox from source just to give it a try and now I can use either method to override the path to plugins.

Mike Kaply explains that some aspects of plugin search path are runtime configurable via "about:config"; though the settings he describes are not present in my build - Mozilla/5.0 (X11; Linux i686 on x86_64; rv:24.0).

http://mike.kaply.com/2012/02/16/how-.../how-firefox-loads-plugins/

In my case I needed to run a 32 bit build on amd64 linux ubuntu.

I wanted to avoid setting the global plugin path under /usr/lib/mozilla/plugins by creating a symlink under the application directory to the 32 bit JRE. I had configured Ubuntu's 'alternatives' framework for both 64 and 32 bit plugins but auto selection wasn't working in this case.

The application directory override seemed to work under version 23 but after upgrade to v.24 the 32 bit java plugin was not being discovered.

I was able to fix this problem by enabling the about:config setting - plugins.load_appdir_plugins - which for my install had been defaulted to 'false' by the build.

It shouldn't be this difficult. Disabling the well described plugin search paths under the user home and app directory is certainly going to cause major heartache to many users.