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Many websites are being blocked as having an untrusted connection.

  • 2 replies
  • 1 has this problem
  • Last reply by cor-el

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The exact message that I am recieving is - "The certificate is not trusted because the issuer certificate is unknown. (Error code: sec_error_unknown_issuer)" I have both deleted the cert8.db file as recommended in this error's troubleshooting entry, and reset Firefox as recommended on another support entry. Neither have resolved the issue. This message has appeared on all Google websites, PayPal and RBS (Royal Bank of Scotland).

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If you have an antivirus or firewall that provides web protection, double check those settings to make sure that these sites are allowed. For example, Avast has a Web Shield that requires some sites to be on an exclusion list to work properly (otherwise it brings you to the page you are seeing).

Edit: These settings are found in the antivirus/firewall program itself and not in Firefox.

Modified by CoryMH

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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 the intermediate certificates that are used in the Details tab.