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.

After downloading 4.0 I get this message: JavaScript application can't create mcafee plug-in object: TypeError: components.classes[cid] is undefined

  • 3 replies
  • 49 have this problem
  • 9 views
  • Last reply by mrbillshaw

Nima
Nima
more options

I finished downloading Firefox 4.o to my Mac OS.X. When I try to open a website I get the message: [JavaScript Application] can't create mcafee plug-in object: TypeError: Components.classes[cid] is undefined If I click the OK button, the site opens, but without the McAfee alert at the bottom of the window. I had just downloaded 3.6.16, and got box suggesting download version 4.0 for better security, but that seems to be where the problem is!

I finished downloading Firefox 4.o to my Mac OS.X. When I try to open a website I get the message: [JavaScript Application] can't create mcafee plug-in object: TypeError: Components.classes[cid] is undefined If I click the OK button, the site opens, but without the McAfee alert at the bottom of the window. I had just downloaded 3.6.16, and got box suggesting download version 4.0 for better security, but that seems to be where the problem is!

Chosen solution

That indicates that an add-on you are using is not compatible, considering the other errors it is possibly the McAfee add-on. To confirm what add-on is causing this use the procedure in this link - https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

Read this answer in context 👍 1

All Replies (3)

TonyE
TonyE
  • Moderator
more options

Chosen Solution

That indicates that an add-on you are using is not compatible, considering the other errors it is possibly the McAfee add-on. To confirm what add-on is causing this use the procedure in this link - https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

Nima
Nima Question owner
more options

I tried the troubleshooting+extensions solution, deleting the McAfee extension. Firefox is now up and running. Thank you!

mrbillshaw
mrbillshaw
more options

In my case it was Billeo - I got the error on an HP Laptop with Windows 7 64bit but not on an iMac with the same OS under VMware Fusion. May be some sort of hardware related problem.