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

Secure Connection Failure

  • 7 replies
  • 2 have this problem
  • 6 views
  • Last reply by drmayeda1

more options

Hello. Since installing Thunderbird v91.5 on my new Windows 11 laptop, I get a Secure Connection Failure when trying to get add-ons. This doesn't happen with my other PC's running Windows 10. Anyone have a solution? -- Thanks!

Hello. Since installing Thunderbird v91.5 on my new Windows 11 laptop, I get a Secure Connection Failure when trying to get add-ons. This doesn't happen with my other PC's running Windows 10. Anyone have a solution? -- Thanks!

All Replies (7)

more options

Look at the anti virus on your new device. Many of them "hack" secure connections to scan the content before it gets to the application. The result of this is they use dodgy certificates to decrypt mail and Thunderbird does not see them as valid as they are not issued in the chain of trust. They are self signed by the anti virus company. I don't trust any of them.

more options

Much appreciated Matt, but I'm sure what to look for in the Virus and Threat Protection menu options. I'm using Windows Security (that came with Windows 11).

more options

I can not help you with windows 11. My new computer (3 months now) is not compatible apparently.

more options

No worries. Thanks anyway.

more options

I have the same problem with win11. enclosed is a screenshot of the message I received

more options

Last I heard of that (some time ago) it was done by AVAST. Do you have an anti virus that purports to scan secure connections?

more options

norton 360 but it hasn't generated a message before that or windows defender