Troubleshoot *https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

I am having the same problem,no installed plugins recognized by Firefox.

It is possible that there is a problem with the file(s) that store the extensions registry. Delete the files extensions.* (e.g. extensions.sqlite, extensions.ini) and compatibility.ini in the Firefox profile folder to reset the extensions registry. *https://support.mozilla.org/kb/Profiles New files will be created when required. See "Corrupt extension files": *http://kb.mozillazine.org/Unable_to_install_themes_or_extensions *https://support.mozilla.org/kb/Unable+to+install+add-ons If you see disabled, not compatible, extensions in "Tools > Add-ons > Extensions" then click the Tools button at the left end side of the Search Bar ("Find Updates" button in older Firefox versions) to check if there is a compatibility update available. If this hasn't helped then also try to delete the addons.sqlite file. Try to delete the pluginreg.dat file in the Firefox Profile Folder and maybe addons.sqlite as well to reset the plugin registry databases. See Re-initializing the plugins database: *https://support.mozilla.org/kb/troubleshoot-issues-with-plugins-fix-problems ---- You can use this button to go to the Firefox profile folder: *Help > Troubleshooting Information > Profile Directory: Show Folder *http://kb.mozillazine.org/Profile_folder_-_Firefox