There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.

http://www.ehow.com/how_11385212_troubleshoot-reset-connection-firefox.html

https://support.mozilla.org/en-US/kb/server-not-found-connection-problem

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

http://kb.mozillazine.org/Error_loading_websites

https://www.bing.com/search?q=web+site+access+denied

https://support.mozilla.org/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER

This Connection is Untrusted is sometimes caused because the computer system clock is wrong. Check the time / date / time zone settings.

Those links give me:

SSL_ERROR_NO_CYPHER_OVERLAP

When I test the domains using this tool:

https://www.ssllabs.com/ssltest/

They score an "F" for connection security.

Their testbed was not able to connect using Firefox 46 or 47, Chrome 51, Edge, or Internet Explorer 11. Basically, this site is unusable in modern browsers due to how bad its security is.

So the administrator should update these sites ASAP if it is important that users have secure connections and that the site be able to trust those connections. Maybe they don't handle important enough data to worry about that.

If your company believes you should use these servers despite the risk that no communications are actually private -- due to the combination of TLS 1.0 and RC4 cipher -- Firefox does have a mechanism to allow the specific servers:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste TLS and pause while the list is filtered

(3) Select (for example, triple-click) and copy the following line:

citrix.cogecodata.net,qticsg.quiettouch.com

(4) Double-click the security.tls.insecure_fallback_hosts preference and:

(A) If the preference currently has some value, add a comma to the end and then paste the additional text and click OK

(B) If the preference does not have any value, paste and click OK

To test, reload the insecure pages using Ctrl+Shift+r to bypass the cache.

Added a screenshot