Hi, Please check if '''DigiCert Inc.''' which comes with a standard Firefox installation is listed in '''Tools''' ('''Alt''' + '''T''') > '''Options''' > '''Advanced''' > '''Encryption''' > '''View Certificates''' > '''Authorities'''. ............................................................................................................................... Useful links: [https://support.mozilla.com/en-US/kb/Options%20window All about Tools > Options] [http://kb.mozillazine.org/About:config Going beyond Tools > Options - about:config] [http://kb.mozillazine.org/About:config_entries about:config Entries] [https://support.mozilla.com/en-US/kb/Page%20Info%20window Page Info] Tools (Alt + T) > Page Info, Right-click > View Page Info [https://support.mozilla.com/en-US/kb/Keyboard%20shortcuts Keyboard Shortcuts] [https://support.mozilla.com/en-US/kb/Viewing%20video%20in%20Firefox%20without%20a%20plugin Viewing Video without Plugins] [http://kb.mozillazine.org/Profile_folder_-_Firefox Firefox Profile Folder & Files] [https://developer.mozilla.org/en/Command_Line_Options#Browser Firefox Commands] [https://support.mozilla.com/en-US/kb/Basic%20Troubleshooting Basic Troubleshooting] [https://support.mozilla.com/en-US/kb/common-questions-after-upgrading-firefox-36 After Upgrading] [https://support.mozilla.com/en-US/kb/Safe%20Mode Safe Mode] [http://kb.mozillazine.org/Problematic_extensions Problematic Extensions] [https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes Troubleshooting Extensions and Themes] [https://support.mozilla.com/en-US/kb/Troubleshooting%20plugins Troubleshooting Plugins] [http://kb.mozillazine.org/Testing_plugins Testing Plugins]

Yes, the DigiCert Inc is in the list. Lizette

I've attached a screenshot. Is it the same in the '''Add Exception...''' > '''View''' > '''Details''', '''Certificate Hierarchy''' (chain)? If '''When an OSCP server connection,...''' is enabled in '''Tools''' ('''Alt''' + '''T''') > '''Options''' > '''Advanced''' > '''Encryption''' > '''Validation''', this error may be temporary. The error may also happen if you are connecting through a proxy or a security software that connects on behalf of the browser. If possible you should also try to update Firefox. I think version 5.0 is no longer officially maintained.

Please also [http://kb.mozillazine.org/SSL_Security_Error see this.]

Who is the issuer of that certificate? I see a different certificate chain for that specific domain (Akamai Subordinate CA 3 -> GTE CyberTrust Global Root), so they may be using more servers for load balancing and you may get a different server. You can retrieve the certificate and check details like who issued certificates and expiration dates of certificates. * Click the link at the bottom of the error page: "I Understand the Risks" Let Firefox retrieve the certificate: "Add Exception" -> "Get Certificate". * Click the "View..." button and inspect the certificate and check who is the issuer. You can see more Details like intermediate certificates that are used in the Details pane.