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 I launch Firefox 4.0 I get the following message "TypeError: Components.classes[cid]is undefined. How do I fix this?

  • 1 vastus
  • 6 on selline probleem
  • 1 view
  • Viimati vastas TonyE

more options

When I click "ok" the pop up window clears and FireFox opens. I believe this error is also preventing Privacy Protect from activating in FireFox.

When I click "ok" the pop up window clears and FireFox opens. I believe this error is also preventing Privacy Protect from activating in FireFox.

All Replies (2)

more options

This is probably due to an add-on that is not compatible with Firefox 4. For details of how to troubleshoot that see https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

more options

I determined one of the security programs was not compatible with Firefox 4.0. After disabling the program Firefox 4.0 works just fine.