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

ابحث في الدعم

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.

Error "TypeError: Components.classes[cid] is undefined" when opening Firefox - every time it is opened!!

  • 2 (ردّان اثنان)
  • 40 have this problem
  • 1 view
  • آخر ردّ كتبه sharondilworth

sharondilworth
sharondilworth
more options

Since installing Firefox 4 I receive this error message "TypeError: Components.classes[cid] is undefined" each time Firefox is opened and when trying to access some websites. Very aggravating!!

Since installing Firefox 4 I receive this error message "TypeError: Components.classes[cid] is undefined" each time Firefox is opened and when trying to access some websites. Very aggravating!!

الحل المُختار

That indicates that you are using an add-on that is not compatible with Firefox 4. For details of how to troubleshoot this to find out what one is causing the problem see https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

Read this answer in context 👍 1

All Replies (2)

TonyE
TonyE
  • Moderator
more options

الحل المُختار

That indicates that you are using an add-on that is not compatible with Firefox 4. For details of how to troubleshoot this to find out what one is causing the problem see https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

sharondilworth
sharondilworth صاحب السؤال
more options

After I disabled the last add-on that was installed prior to upgrading to version 4 the error was eliminated. Thanks!!