Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

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

I keep getting "exc in ev handl: Error: Bad NPObject as private data! when I open new browser windows in Firefox 3.6 which I just let the computer upgrade to a couple of days ago. Make this error box go away please!!!!

more options

the error box keeps dinging and I have to x out of it every time I either open a new browser window or try to close others. It's annoying. The only change i made to my computer was that I upgraded to the newest version of Firefox a couple of days ago and that's when it started. Please help me. I can't work like this on my computer having that box come up every time.

It says [JavaScript Application] in the bar and then next to the yellow triangle below it says "Exc in ev handl: Error: Bad NPObject as private data!"

How do I make it go away?

the error box keeps dinging and I have to x out of it every time I either open a new browser window or try to close others. It's annoying. The only change i made to my computer was that I upgraded to the newest version of Firefox a couple of days ago and that's when it started. Please help me. I can't work like this on my computer having that box come up every time. It says [JavaScript Application] in the bar and then next to the yellow triangle below it says "Exc in ev handl: Error: Bad NPObject as private data!" How do I make it go away?

All Replies (1)

more options

Please see solution in http://kb.mozillazine.org/Problematic_extensions for "McAfee Site Advisor".

(Windows): For best results you should uninstall McAfee Site Advisor from Control Panel > add/change programs (Programs and Features). Reboot the system. Then Reinstall from http://www.siteadvisor.com/ and reboot the system. When installing refuse other suggested (crapware) applications.


Please mark "Solved" one answer that will best help others with a similar problem -- hope this was it.