Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

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.

How to fix: TypeError: Components.classes[cid_siterank] is undefined

  • 1 reply
  • 39 have this problem
  • 10 views
  • Last reply by cor-el

meldan111
meldan111
more options

how do you fix "TypeError: Components.classes[cid_siterank] is undefined I have had nothing but problems with firefox. Every time I try to manuver around the above error message appears, and I can't go any further until I click on it.

how do you fix "TypeError: Components.classes[cid_siterank] is undefined'' I have had nothing but problems with firefox. Every time I try to manuver around the above error message appears, and I can't go any further until I click on it.

All Replies (1)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).