Issues have been previously linked to the McAfee Site Advisor extension. Try to disable it and see if the problem persists.

http://service.mcafee.com/faqdocument.aspx?id=TS100162 How to uninstall SiteAdvisor

To disable it: Type "about:addons" in the Location bar Find the extension and click on its "Disable" button

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/secure-connection-failed-error-message

https://support.mozilla.org/en-US/kb/connection-untrusted-error-message

http://kb.mozillazine.org/Error_loading_websites

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

I uninstalled McAfee Web Adviser (I don't run McAfee Site Adviser) as suggested. WGTE Knowledge Stream still does not run properly. I reinstalled McAfee Web Adviser. I then installed Google Chrome (which asked me to attach McAfee Web Adviser, which I did). The Knowledge Stream site runs properly under Chrome. This indicates that the McAfee add-on has no deleterious effect but that the problem lies in some yet unknown interaction of Firefox with Knowledge Stream. I'll jut use Chrome for this site. Regards, Ernest Lippert

I uninstalled McAfee Web Adviser (I don't run McAfee Site Adviser) as suggested. WGTE Knowledge Stream still does not run properly. I reinstalled McAfee Web Adviser. I then installed Google Chrome (which asked me to attach McAfee Web Adviser, which I did). The Knowledge Stream site runs properly under Chrome. This indicates that the McAfee add-on has no deleterious effect but that the problem lies in some yet unknown interaction of Firefox with Knowledge Stream. I'll jut use Chrome for this site. Regards, Ernest Lippert (Sorry if this is a double posting(

Have you checked the other links I posted?