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.

Avatar for Username

Buscar en Ayuda

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

Este tema ha sido archivado. Haz una nueva pregunta si necesitas ayuda.

Error message when opening Thunderbird

  • 1 respuesta
  • 1 tiene este problema
  • 27 visitas
  • Última respuesta de Tonnes

norm629
norm629
more options

The following message show in the message box when I open Thunderbird. The program seems to word fine, I can send and receive mail. The message will disappear when I click on an email. version 52.2.1

"Secure connection failed start.thunderbird.net uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. Error code: <a id="errorCode" title="SEC_ERROR_UNKNOWN_ISSUER">SEC_ERROR_UNKNOWN_ISSUER</a>"

The following message show in the message box when I open Thunderbird. The program seems to word fine, I can send and receive mail. The message will disappear when I click on an email. version 52.2.1 "Secure connection failed start.thunderbird.net uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. Error code: <a id="errorCode" title="SEC_ERROR_UNKNOWN_ISSUER">SEC_ERROR_UNKNOWN_ISSUER</a>"

Todas las respuestas (1)

Tonnes
Tonnes
  • Locale Leader
more options

Please have a look at the How to troubleshoot security error codes on secure websites support article for Firefox and make sure you do what is required for any antivirus software. Most likely, it is interfering with your Thunderbird website connections - start.thunderbird.net is the startup web page, and perhaps you may experience the same in the Add-ons Manager for the AMO website. If you also user Firefox, you may suffer the same issue there.

Also see this question.