Try to create symlinks in /usr/lib/browser-plugins/ or ~/.mozilla/plugins

See also:

• https://developer.mozilla.org/en/Gecko_Plugin_API_Reference/Plug-in_Basics#Plug-in_Detection

not helping, tried all of that earlier.

You have the correct plugins for your Firefox version?

I assume that you've installed 32 bit versions of Firefox 18 and Firefox 15 (/usr/lib/ is for 32 bit plugins)?

Well I think that this might be the issue, but have no idea how to deal with it. The Nightly Build comes with 64bit option, so that's what I've grabbed. The FF15 comes only in one option, and I have no idea if that's 32 or 64 bit. When browsing /usr/lib64 and /usr/lib32 I've noticed missing mozilla folders under lib32. The thing is, I've tried to symlink both: sudo ln -s /usr/lib/mozilla /usr/lib32 or sudo ln -s /usr/lib/firefox /usr/lib32

but still had no success. So maybe I do have 64bit plugins installed, but I think I've installed the 32bit libraries for 64bit support, and while that's not helping, I have no idea how to install them in both versions.

btw, here's my user agent that I think indicated my 32bit FF15, but I'm not sure: Build identifier: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:15.0) Gecko/20100101 Firefox/15.0.1

The Firefox 15 release comes as a 32 bit version.
The user agent only shows that you are on a 64 bit Linux platform.

So you need 32 bit versions of the plugins and Firefox needs to find them.

Does Firefox 15 find any plugins?

You can set the plugin.expose_full_path pref to true on the about:config page to see the full path of plugins on the about:plugins page.

• http://kb.mozillazine.org/Issues_related_to_plugins#Identifying_installed_plugins

It is best not to leave that pref set to true as it exposes that full path to web servers via the navigator.plugins object, so reset that pref to false after you are done with the about:plugins page.

• http://kb.mozillazine.org/about:config

There are absolutely no plugins discovered in FF15, the tab is empty, I've mentioned it in my prior posts. And the UA says "Linux i686 on x86_64" while in Iceweasel / Nightly it says "Linux x86_64"

OMG finally!!! downloaded 32bit flash11 from: http://get.adobe.com/flashplayer/completion/?installer=Flash_Player_11.2_for_other_Linux_%28.tar.gz%29_32-bit

1. mkdir ~/.mozilla/plugins
2. tar xvfz install_flash_player_11_linux.i386.tar.gz
3. cp libflashplayer.so ~/.mozilla/plugins/
4. remove all other files from tarball and restart FF15
5. check about:plugins