I am using a RHEL 64 bit system. I successfully have been able to install the Firefox extension, configure and use it with root.  However, it will not work when I log into as a standard user. I am using firefox 45.1.I have put the information in /usr/lib64/firefox/browser/extensions but I cant seem to make it work.This system isn't on a network which causes more challenges. 
Can't get firefox extension to work for all users
rhel;firefox