We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

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

firefox issue with Bitdefener certificate blocking sites - "SEC_ERROR_UNKNOWN_ISSUER" on secure websites

  • 1 svar
  • 1 har dette problemet
  • 4 views
  • Siste svar av FredMcD

more options

Since our users have updated to the latest version of firefox, our antivirus BitDefender certificate has to be canceled during installation to avoid the the error: "SEC_ERROR_UNKNOWN_ISSUER" on secure websites Firefox was working fine with our Bitdefender certificate until version 5.8

Please send us direction to fix the issue. Thank you, Rene Manzo

Since our users have updated to the latest version of firefox, our antivirus BitDefender certificate has to be canceled during installation to avoid the the error: "SEC_ERROR_UNKNOWN_ISSUER" on secure websites Firefox was working fine with our Bitdefender certificate until version 5.8 Please send us direction to fix the issue. Thank you, Rene Manzo

All Replies (1)

more options

I called for more help.


Separate Security Issue: Update your Flash Player or remove it using these links; http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html Uninstall Flash Player | Windows http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html Uninstall Flash Player | Mac

Note: Windows users should download the ActiveX for Internet Explorer. and the plugin for Plugin-based browsers (like Firefox).

Note: Windows 8 and Windows 10 have built-in flash players and Adobe will cause a conflict. Install the plugin only. Not the ActiveX.

Flash Player Version: Version 29.0.0.113

https://get.adobe.com/flashplayer/ Direct link scans current system and browser Note: Other software is offered in the download. <Windows Only>

https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, Win IE . . . .) Note: Other software is offered in the download. <Windows Only> +++++++++++++++++++ See if there are updates for your graphics drivers https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration