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.

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.

Wont work with Windows 10 and Avast!

  • 1 reply
  • 1 has this problem
  • 1 view
  • Last reply by user633449

lordsnooty
lordsnooty
more options

Mozilla Firefox problems:

a). Wont open in Windows 10 - gives message: "Secure connection failed"

b). When I open "Extensions", message reads: " Avast on line security could not be verified in Firefox. Proceed with CAUTION"

PLEASE ADVISE.....

Mozilla Firefox problems: a). Wont open in Windows 10 - gives message: "Secure connection failed" b). When I open "Extensions", message reads: " Avast on line security could not be verified in Firefox. Proceed with CAUTION" PLEASE ADVISE.....

All Replies (1)

user633449
user633449
more options

Avast has been causing many issues in Firefox lately, especially on Windows 10. I'd suggest disabling the Avast add-on, it is useless anyway.