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This Connection is Untrusted, techinical detail (The certificate is not trusted because no issuer chain was provided. (Error code: sec_error_unknown_issuer))

  • 4 replies
  • 45 have this problem
  • 2 views
  • Last reply by cor-el

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Mozilla shows this error for all site including Google. And after confirming security exception the site loads but without following any styling (css)

Mozilla shows this error for all site including Google. And after confirming security exception the site loads but without following any styling (css)

All Replies (4)

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Check out why the site is untrusted (click "Technical Details to expand that section) and if this is caused by a missing intermediate certificate then see if you can install this intermediate certificate from another source.

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.

If "I Understand the Risks" is missing then this page may be opened in an (i)frame and in that case try the right-click context menu and use "This Frame: Open Frame in New Tab".

Some firewalls monitor secure (https) connections and send their own certificate instead of the website's certificate.

For ESET see:

  • ESET setup -> advanced setup -> extend web and email tree -> SSL
  • SSL protocol: Do not scan SSL protocol
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Problem Solved!

Thank you cor-el !

Your these lines helped me

"For ESET see:

ESET setup -> advanced setup -> extend web and email tree -> SSL SSL protocol: Do not scan SSL protocol " But the eset (eset smart security 5) path was a bit different, i.e the path was:

ESET setup -> advanced setup -> extend web and email tree ->Protocol filtering -> <option>Enable application protocol content filtering<option>

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Help Me ..!! :(

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Hi herry990

Could you please start a new thread for your question instead of posting in an older existing thread?

Then you can provide more information like your operating system and installed extensions and installed plugins.

In case of crashes also please add some recent crash IDs that you can find on the about:crashes page and that start with a "bp-" prefix


What does it say under the technical details?

If "I Understand the Risks" is missing then this page may be opened in an (i)frame and in that case try the right-click context menu and use "This Frame: Open Frame in New Tab".