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.

Hmm, in past threads, this could occur if the page contained even a single image that didn't load correctly. I think there are two things to check:

(1) Is this page generated by your internet service provider? (2) Is this page generated by an extension (malware)?

Look for a link on the page that says anything like "about this page", "why do I see this page", etc. It may be in small print toward the upper right or bottom of the page.

If you follow that link, if this is a "service" of your provider, there should be an opt-out option.

If there's no opt-out, usually it is caused by an extension. To check for that, open the Add-ons page. Either:

• Cmd+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions. Then check the list on the right. Bear in mind that all extensions are optional -- none come with Firefox. Disable anything that you do not remember installing or that does not have obvious value in your daily browsing. Remove anything suspicious.

Often a link will appear above at least one disabled/removed extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Any improvement?