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 activate firefox I get this message "TypeError: Components.classes[cid] is undefined" Why?

  • 1 phendula
  • 22 inale ngxaki
  • 1 view
  • Impendulo yokugqibela ngu cor-el

more options

As soon as I activate Firefox I get a pop-up with that message and an OK button which has to be pressed before the program continues.

I am running Windows XP and Firefox 3.6 on an Acer Laptop.

As soon as I activate Firefox I get a pop-up with that message and an OK button which has to be pressed before the program continues. I am running Windows XP and Firefox 3.6 on an Acer Laptop.

All Replies (1)

more options

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

  • Don't make any changes on the Safe mode start window.

See:

If it does work in Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears.

  • Use "Disable all add-ons" on the Safe mode start window to disable all extensions.
  • Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")