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

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

This thread was archived. Please ask a new question if you need help.

"SEC_ERROR_UNKNOWN_ISSUER".

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

esw_dk
esw_dk
more options

I have installed a SSL certificate on our server which hosts https://slotshotel.dk. In Firefox I got the error "SEC_ERROR_UNKNOWN_ISSUER" on multiple PC's and different versions.

In all other browsers the certificate works well.

Google Chrome 58.0.3029.110 (64-bit) Microsoft Edge 38.14393.1066.0 Internet Explorer, 11.1198.14393.0 

What to do?
I have installed a SSL certificate on our server which hosts https://slotshotel.dk. In Firefox I got the error "SEC_ERROR_UNKNOWN_ISSUER" on multiple PC's and different versions. In all other browsers the certificate works well. Google Chrome 58.0.3029.110 (64-bit) Microsoft Edge 38.14393.1066.0 Internet Explorer, 11.1198.14393.0 What to do?

All Replies (2)

FredMcD
FredMcD
more options
uses an invalid security certificate SSL_ERROR_BAD_CERT_DOMAIN
configured their website improperly

How to troubleshoot the error code "SEC_ERROR_UNKNOWN_ISSUER" on secure websites https://support.mozilla.org/en-US/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

Who is the issuer of the certificate?

You can click the "Advanced" button to expand this section to see extra details. If the certificate is not trusted because no issuer chain was provided (SEC_ERROR_UNKNOWN_ISSUER) then click the blue error message to expand this section and to show the certificate chain. You can paste the full base64 encoded certificate chain in a reply. Then we can check the issuer.