hi, go to the firefox menu ≡ > help ? > troubleshooting information, click on profile folder/show folder and close all firefox windows afterwards. a windows explorer window should open up - in there rename or delete the file named cert8.db - it contains all your customizations to the certificate store & will be regenerated again the next time you launch the browser.

Hi Philipp, Thanks for the prompt reply, but unfortunately this does not solve my problem. I should have made it clear that I want to permanently remove the exception, whereas your suggested solution would regenerate it again on the next start-up. Also, although you say 'a windows explorer window should open up,' it did not do so for me. Furthermore, I now notice that when I access the 'suspect' website, there's a reference to the fact that I have designated it as an exception - which I don't want it to be! Does this help at all? Many thanks anyhow. kevindu.

Did you look for this exception under the servers tab in the Certificate Manager?

Try to rename the cert8.db file (cert8.db.old) and delete the cert_override.txt file in the Firefox profile folder to remove intermediate certificates and exceptions that Firefox has stored.

If that has helped to solve the problem then you can remove the renamed cert8.db.old file. Otherwise you can rename (or copy) the cert8.db.old file to cert8.db to restore the previously stored intermediate certificates. Firefox will automatically store intermediate certificates when you visit websites that send such a certificate.

You can use this button to go to the current Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

kevindu said

I now notice that when I access the 'suspect' website, there's a reference to the fact that I have designated it as an exception - which I don't want it to be!

Where is Firefox indicating that you made an exception for the site?

All the previous replies relate to getting an Untrusted Connection page, expanding the section called "I understand the risks" and using the "Add Exception" button to tell Firefox to trust the site's SSL certificate even though Firefox would not normally trust it.

If you did something different, then that information may well be stored in a different dialog/file than a certificate exception.

Many thanks to philipp. jscher2000, and cor-el for jointly directing me down the right path to enable me to solve my problem. Thanks again!

Regards, kevindu