Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Avatar for Username

Pomoc pśepytaś

Glědajśo se wobšudy pomocy. Njenapominajomy was nigda, telefonowy numer zawołaś, SMS pósłaś abo wósobinske informacije pśeraźiś. Pšosym dajśo suspektnu aktiwitu z pomocu nastajenja „Znjewužywanje k wěsći daś“ k wěsći.

Learn More

Toś ta nitka jo se archiwěrowała. Pšosym stajśo nowe pšašanje, joli trjebaśo pomoc.

Cannot open gmail in Firefox browser.

  • 1 wótegrono
  • 1 ma toś ten problem
  • 1 naglěd
  • Slědne wótegrono wót Happy112

PerfectGrammar
PerfectGrammar
more options

Works fine in Internet Explorer. Firefox is up to date and cookies are enabled and have been cleared. Google.com opens.

This is error message:

Your connection is not secure

The owner of mail.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.

Works fine in Internet Explorer. Firefox is up to date and cookies are enabled and have been cleared. Google.com opens. This is error message: Your connection is not secure The owner of mail.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.

Wšykne wótegrona (1)

Happy112
Happy112
more options

Hi   !

There is security software like Avast and Kaspersky and BitDefender and ESET that intercepts secure connections and sends their own certificate or that incorporates special web shielding features that can block content.

See : https://support.mozilla.org/en-US/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER
Your system details don't show what security software you're running, but try and disable it and see if that makes a difference.