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When I open firefox 4 or a new window I get an error message "components.classes[cid] is undefined" how do I fix this

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  • Last reply by cor-el

pc976
pc976
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I upgraded to firefox 4 and now whenever I open the browser or a new window in the browser I get an error message that reads "Components.classes[cid] is undefined. How do I fix this message. I have reinstalled firefox 4 three times and still get the message. I am running windows 7 pro

I upgraded to firefox 4 and now whenever I open the browser or a new window in the browser I get an error message that reads "Components.classes[cid] is undefined. How do I fix this message. I have reinstalled firefox 4 three times and still get the message. I am running windows 7 pro

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cor-el
cor-el
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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).

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")