This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Èròjà atẹ̀lélànà yii ni a ti fi pamọ́ fọ́jọ́ pípẹ́. Jọ̀wọ́ béèrè ìbéèrè titun bí o bá nílò ìrànwọ́.

Why do I always see "www.mozilla.org uses an invalid security certificate" whenver I start Thunderbird?

  • 2 àwọn èsì
  • 2 ní àwọn ìṣòro yìí
  • 1 view
  • Èsì tí ó kẹ́hìn lọ́wọ́ Toad-Hall

more options

Why is the following displayed in the message display area of Thunderbird whenever I start Thunderbird?

Secure connection failed

www.mozilla.org uses an invalid security certificate. The certificate is not trusted because no issuer chain was provided. (Error code: sec_error_unknown_issuer)

   This could be a problem with the server's configuration, or it could be someone trying to impersonate the server.
   If you have connected to this server successfully in the past, the error may be temporary, and you can try again later.

Or you can add an exception…

Selecting the link to "add an exception" is dead, and doesn't display anything additional.

Why is the following displayed in the message display area of Thunderbird whenever I start Thunderbird? Secure connection failed www.mozilla.org uses an invalid security certificate. The certificate is not trusted because no issuer chain was provided. (Error code: sec_error_unknown_issuer) This could be a problem with the server's configuration, or it could be someone trying to impersonate the server. If you have connected to this server successfully in the past, the error may be temporary, and you can try again later. Or you can add an exception… Selecting the link to "add an exception" is dead, and doesn't display anything additional.
Ìsopọ̀ yíyà aṣàfihàn

All Replies (2)

more options

I neglected to mention that I'm running Thunderbird version 31.4.0 under Windows 10 Pro 64-bit Technical Preview build 9926. But I experience the same problem while running Thunderbird under Windows 8.1 Pro 64-bit.

more options