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

Websites don't load - troubleshoot and fix error messages

http://kb.mozillazine.org/Error_loading_websites

What do the security warning codes mean

Thanks,

However, that does not explain why there is not a problem on another PC running the same s/w. Both PC's are running the same AV s/w. It also does not explain why if I search via Google and click on the link, I do not get the error. It must be something in the FF settings on my PC, although a restart in safe mode should resolve that, but it does not. Also, once the page loads after pressing F5, it will load correctly in other tabs, so that rules out any issue with AV s/w.

I am reluctant to try an FF reset as I will lose all my browsing history.

Regards,

Steve

Refreshing Firefox {web link} is a LAST RESORT ! !

Refreshing Firefox -- easily fix most problems

If you're having problems with Firefox, refreshing it can help. The refresh feature fixes many issues by restoring Firefox to its factory default state while saving your essential information like bookmarks and open tabs. Everything else, like user settings and add-ons, are removed. Note: Refresh saves your old profile to the desktop in a folder called Old Firefox.

OK, refreshing seems to have done the trick, is there a way I can restore my addons to the refreshed FF??

Regards,

Steve

I have restored my addons and extensions from Old Firefox Data and all seems good. Although, it seems that about every six months I have to refresh FF, which is not ideal.

Thanks for your help.

Regards,

Steve