hello viper, maybe the following article explains what is going on & how to address it: http://www.ghacks.net/2013/05/15/why-you-may-have-lost-access-to-plugins-or-extensions-in-firefox-21/ (i'm not entirely sure if it also applies to linux though)

I am having the problem with Firefox running on Windows (XP to be exact). Since it came with Windows 8, I do not run Windows on my machine (which I posted the question from). I didn't know that it was going to try and attach machine info automatically. I pasted the information from the Windows XP Firefox versions manually in the additional information section of the question.

Anyway, for some reason I never ran into that website with my initial searches for this problem. Why doesn't the Firefox installer move or copy the plugins folder if it changes the location of it? Now I need to script a Firefox installer fix for all workstations and turn off auto-updates of Firefox since this is the second time something went wrong with a new Firefox version in a very short time (19.0.2->20 [unresponsive location bar] and 20.0.1->21 [plugins disappearing without warning]). Mozilla seems to be concentrating too much on this decades Windows ME and ignoring the majority of their existing installations. Ok, off soapbox and feeling better. The good news is that the plug-in wasn't disabled after all.

Thanks!

I am also having this problem. I am not a super-user and am not comfortable working with config files at all. I tried copying the plugins from Firefox/plugins to Firefox/browser/searchplugins, but it didn't make a difference. Citrix does not appear as a Firefox plug-in. Since I don't use IE, I really need this fixed. I use the plug in to work from home and can't do it now. When I try to re-install, I get a message that the plugin is already installed. Is there a way to fix this that doesn't require me to be a PC expert?

hello, put the plugin files into firefox\browser\plugins not into searchplugins!

can you post a screen shot?