INSTALL LibX Concordia
On this page
LibX Extensions for Firefox and Chrome
If Firefox displays a message "Firefox prevented... from installing software on your computer", click on "Allow" to show that you permit this installation. You can then click "Ok" and click on the "Install LibX" link again. Restart Firefox.
LibX is currently supported only for Mozilla Firefox and Google Chrome. Internet Explorer is not supported. To see the latest news about LibX from the developers themselves, see Announcements on the LibX site.