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

www.google.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. Help

  • 3 replies
  • 1 has this problem
  • 1 view
  • Last reply by John99

more options

Firefox updated it self yesterday now I keep getting the error message that sites are using 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. I am using Bull guard internet security How do I fix this please it's driving me nuts seriously considering just uninstalling Firefox

Firefox updated it self yesterday now I keep getting the error message that sites are using 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. I am using Bull guard internet security How do I fix this please it's driving me nuts seriously considering just uninstalling Firefox
Attached screenshots

Modified by traceygl

All Replies (3)

more options

Greetings traceygl This issue has been on the forum. Please read here. There are all ways to solve your problem PS. When the problem occurred, it is often solved by manually refreshing the browser (download the package from the official Mozilla website)

I hope this will help you. Thank you for contacting support forum!

Modified by Anticisco Freeman

more options

Please check the version of Firefox you are using. You should be using a Fx44 now (Fx 45 next week).

Firefox 44 relaxed its security requirements to allow for use of security software that itself uses insecure certificates. As it stands bulguard is causing the issue because it effectively tries to impersonate google. Disabling bulguard will solve your problem.

Also any others with similar problems check that your computer clock is set to the correct time, note other security software also causes this issue,it is not restricted to bulguard.

Some common related issues an solutions see

more options

P.S. Windows often has its own security software. Windows 10 will have a built in Firewall and Anti Virus software. Firefox itself by default offers basic anti phishing and malware protection

Note if you turn off bulguards interference with Firefox you will still be able to use bulguard's AntiVirus features as an alternative to the free Windows AV that you already have.