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.

How do I stop Firefox from keeping me from going to every site it claims is dangerous?

  • 2 majibu
  • 1 ana tatizo hili
  • 1 view
  • Last reply by cor-el

Bbglas
Bbglas
more options

This is what I get for google email site for example: Your connection is not secure

The owner of www.google.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.

This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely. As a result, it is not possible to add an exception for this certificate.

Learn more…

Report errors like this to help Mozilla identify and block malicious sites

This is what I get for google email site for example: Your connection is not secure The owner of www.google.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website. This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely. As a result, it is not possible to add an exception for this certificate. Learn more… Report errors like this to help Mozilla identify and block malicious sites

All Replies (2)

FredMcD
FredMcD
more options

There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connection certificates and send their own.

https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites

https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message

https://support.mozilla.org/en-US/kb/connection-untrusted-error-message

Websites don't load - troubleshoot and fix error messages

http://kb.mozillazine.org/Error_loading_websites


  • MOZILLA_PKIX_ERROR_MITM_DETECTED
  • 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

You can check if there is more detail available about the issuer of the certificate.

  • click the "Advanced" button show more detail
  • click the blue error text (SEC_ERROR_UNKNOWN_ISSUER) to show the certificate chain
  • click "Copy text to clipboard" and paste the base64 certificate chain text in a reply

If clicking the blue error text doesn't provide the certificate chain then try these steps to inspect the certificate.

  • open the Servers tab in the Certificate Manager
    • Options/Preferences -> Privacy & Security
      Certificates: View Certificates -> Servers: "Add Exception"
  • paste the URL of the website (https://xxx.xxx) in it's Location field

Let Firefox retrieve the certificate -> "Get Certificate"

  • click the "View" button and inspect the certificate

You can see detail like the issuer of the certificate and intermediate certificates in the Details tab.