There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connection certificates and send their own. https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message https://support.mozilla.org/en-US/kb/connection-untrusted-error-message [https://support.mozilla.org/en-US/kb/websites-dont-load-troubleshoot-and-fix-errors?redirectlocale=en-US&redirectslug=Error+loading+web+sites Websites don't load - troubleshoot and fix error messages] http://kb.mozillazine.org/Error_loading_websites [https://support.mozilla.org/en-US/kb/what-does-your-connection-is-not-secure-mean What do the security warning codes mean]

Hi rtkoch1, this particular error code often means Firefox failed to present the site with your personal certificate. Did the site issue you a certificate for access? If so, you may need to import that into Firefox. If this is not related to a personal certificate, I'm not sure why you would get a handshake failure. Could you copy/paste any other information provided on the error page that might shed more light on the problem?

Did you try to close and restart Firefox to see if this recovers from this issue ? Are you using Private Browsing mode ?