"Firefox can't load websites but other browsers can - if you can view websites in browsers other than Firefox. "

Hi everyone: Suddenly Firefox is picky about certificates and won't let me go to most websites. I went to the help article on support.mozilla titled: "Websites don't load - troubleshoot and fix error messages." I tested one of the "insecure connection" websites in I.E., and I.E. opened it. So I clicked "The problem only happens in Firefox." There was this paragraph: "If another web browser works just fine, one of following solutions should fix things: "Firefox can't load websites but other browsers can - if you can view websites in browsers other than Firefox. " I clicked that and ended up back here: "For other error messages that display when you try to view websites in Firefox, see Websites don't load - troubleshoot and fix error messages. " That should look familiar. If I click that link, I end up here: "The problem only happens in Firefox." I have yet to find a solution to try. Help?