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

can't create mcafee plug-in object: TypeError: Components.classes[cid] is undefined

  • 2 ŋuɖoɖowo
  • 9 masɔmasɔ sia le wosi
  • 4 views
  • Nuɖoɖo mlɔetɔ suzimatt

more options

I updated to Firefox 4.0 and ever since then, I get this message when I try to open Firefox:

can't create mcafee plug-in object: TypeError: Components.classes[cid] is undefined

I have a Mac and have McAfee protection for Mac. This problem did not happen before I updated Firefox. Once I click on "OK" Firefox opens.

I updated to Firefox 4.0 and ever since then, I get this message when I try to open Firefox: can't create mcafee plug-in object: TypeError: Components.classes[cid] is undefined I have a Mac and have McAfee protection for Mac. This problem did not happen before I updated Firefox. Once I click on "OK" Firefox opens.

All Replies (2)

more options

This issue is most likely caused by a McAfee extension that isn't working properly and you will have to disable the extension that causes it.

You can also check if there is an update available from McAfee that fixes this problem.

more options

How do I do that? I've tried to find a fix on McAfee's site, but to no avail.