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

When opened http bar shows this and closes immediately (i was able to read it only from screenshot) -> about:newaddon?id={4ED1F68A-5463-4931-9384-8FFF5ED91D92}

  • 2 replies
  • 1 has this problem
  • 1 view
  • Last reply by cor-el

more options

This error began after my refusal to install McAfee SiteAdvisor.

This error began after my refusal to install McAfee SiteAdvisor.

Modified by cor-el

All Replies (2)

more options

What's your computer system and Firefox version?

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

more options

{4ED1F68A-5463-4931-9384-8FFF5ED91D92}: This is the GUID of the McAfee SiteAdvisor (WebAdvisor) extension.

McAfee likely installs this extension globally for Firefox and may insist on enabling this extension. If you do not want to use this extension in Firefox then best is to disable this in your McAfee security software.

Do you see this extension in about:addons? "3-bar" menu button or Tools -> Add-ons -> Extensions

You may also have to disable McAfee plugins.