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When I open Firefox, the browser does not open. Instead I get a small window that says: TypeError: Components.classes[cid] is undefined. How do I fix this?

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I tried to uninstall AVG antiviral software, but it did not uninstall. Next, when I try to open Firefox I get a box popup that says:

TypeError: Components.classes[cid] is undefined.

If I click OK in that box, I can then open Firefox.

Also I can no longer update Java.

Help!

I tried to uninstall AVG antiviral software, but it did not uninstall. Next, when I try to open Firefox I get a box popup that says: TypeError: Components.classes[cid] is undefined. If I click OK in that box, I can then open Firefox. Also I can no longer update Java. Help!

All Replies (2)

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

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Possibly you have "AVG Safe search" extension installed as part of "AVG Free", solution involves reinstalling :AVG Free" without the Link Scanner component see

Other possibilities

If none of the above solve you problem use diagnostic approach...

Modified by David McRitchie