Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Mozilla サポートの検索

サポート詐欺に注意してください。 私たちはあなたに通話やショートメッセージの送信、個人情報の共有を求めることはありません。疑わしい行為を見つけたら「迷惑行為を報告」からご報告ください。

詳しく学ぶ

このスレッドはアーカイブに保管されました。 必要であれば新たに質問してください。

Every website i go on, including Mozilla, gives me a "Connection cannot be trusted" screen with no option to permanently approve it

  • 2 件の返信
  • 7 人がこの問題に困っています
  • 9 回表示
  • 最後の返信者: cor-el

Every website i go to i get the same message. When you click on technical details it reads e.g.:

www.google.com uses an invalid security certificate.

The certificate is not trusted because no issuer chain was provided.

(Error code: sec_error_unknown_issuer)

I tried removing Firefox and reinstalling it. Same result

Every website i go to i get the same message. When you click on technical details it reads e.g.: www.google.com uses an invalid security certificate. The certificate is not trusted because no issuer chain was provided. (Error code: sec_error_unknown_issuer) I tried removing Firefox and reinstalling it. Same result

この投稿は DSaperstein により に変更されました

すべての返信 (2)

hello DSaperstein, which security software are you using?

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

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.

Some security software intercept secure connections and send their own certificate.

Some examples are ESET and Bitdefender.

  • ESET setup -> advanced setup -> extend web and email tree -> SSL
  • SSL protocol: Do not scan SSL protocol
  • BitDefender -> Privacy settings -> disable Scan SSL

If the above didn't help the try to rename the cert8.db file in the Firefox profile folder to cert8.db.old or delete the cert8.db file to remove intermediate certificates that Firefox has stored.

If that 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 previous intermediate certificates.
Firefox will automatically store intermediate certificates when you visit websites that send such a certificate.

If that didn't help then remove or rename secmod.db (secmod.db.old) as well.

この投稿は cor-el により に変更されました