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I receive an Javascript error message everytime I open a web page using Firefox. The error message states:

Error: Type is undefined.  

What does it mean? How do I clear it? I tried updating Java and I still get the message.

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Java has nothing to do with Javascript. – Martín Canaval Jan 20 '13 at 7:28

Disable all extensions. And then drill-down by re-enabling one extension (ie, AVG security tool-bar) at a time and reloading Firefox until you catch the error.

This issue is generally due to outdated extensions.

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