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

Hierdie gesprek is in die argief. Vra asseblief 'n nuwe vraag as jy hulp nodig het.

I am unable to connect with several websites ONLY WHEN using Firefox. I have exhausted all troubleshooting maneuvers to no avail . I have no choice but use Chro

  • 1 antwoord
  • 1 het hierdie probleem
  • 1 view
  • Laaste antwoord deur Shadow110

drmusa
drmusa
more options

I have tried all suggestions but the problem remains. I have been using Google Chrome to manage my internet responsibilities while preferring Firefox.


Your connection is not secure

The owner of mail.yahoo.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website. See below


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

mail.yahoo.com 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: SEC_ERROR_UNKNOWN_ISSUER

I have tried all suggestions but the problem remains. I have been using Google Chrome to manage my internet responsibilities while preferring Firefox. Your connection is not secure The owner of mail.yahoo.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website. See below 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 mail.yahoo.com 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: SEC_ERROR_UNKNOWN_ISSUER

All Replies (1)

Shadow110
Shadow110
more options

Hi, There is security software like Avast/AVG, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate. If you are running any of the above software please check their community forum for a work around to apply settings.

These pages are also for the errors you may have besides relating to the above.

Please let us know if this solved your issue or if need further assistance.