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 am getting a javascript error on startup "Exc in ev handl: TypeError:this.oRoot.enable is not a function"

  • 1 ŋuɖoɖo
  • 6 masɔmasɔ sia le wosi
  • 12 views
  • Nuɖoɖo mlɔetɔ cor-el

more options

When I start Firefox, I get an error box labeled [JavaScript Application] with the message "Exc in ev handl: TypeError: this.oRoot.enable is not a function" I then need to click the OK button before Firefox will start.

When I start Firefox, I get an error box labeled [JavaScript Application] with the message "Exc in ev handl: TypeError: this.oRoot.enable is not a function" I then need to click the OK button before Firefox will start.

All Replies (1)

more options

This issue can be caused by the McAfee Site Advisor extension


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).