This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

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

This thread was archived. Please ask a new question if you need help.

This is the error I always get. How to solve this? "Exc in ev handl: Error: Bad NPObject as private data!"

john_v78
john_v78
more options

This error occurs 50% of the time I use Firefox. It comes up in a small window saying and when I click ok the window will close and another one will open. I thought updating will solve but no. Kindly help me solve.

This error occurs 50% of the time I use Firefox. It comes up in a small window saying and when I click ok the window will close and another one will open. I thought updating will solve but no. Kindly help me solve.

All Replies (1)

Swarnava Sengupta
Swarnava Sengupta
  • Locale Leader
more options

That issue can be caused by the McAfee Site Advisor extension

Start Firefox in Safe 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).