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.

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

Java Script error after updating to 9.0.1

  • 7 balasan
  • 4 ada masalah ini
  • 5 paparan
  • Balasan terakhir oleh Sarek

more options

This one is a bit different from the others posted. My error is "Exc in ev handl: TypeError:brw is undefined. My home pages won't load, much of the Firefox menu isn't working, some toolbar buttons don't work, the url doesn't update, etc.

Restarting in safe mode with add-ons disabled solves the problem. But how do I figure out which add-on is the culprit? If I start Firefox normally with the error, I can't get to the add-ons at all. If I run in safe mode, the add-on screen doesn't let you re-enable them one at a time.

Ideas?

This one is a bit different from the others posted. My error is "Exc in ev handl: TypeError:brw is undefined. My home pages won't load, much of the Firefox menu isn't working, some toolbar buttons don't work, the url doesn't update, etc. Restarting in safe mode with add-ons disabled solves the problem. But how do I figure out which add-on is the culprit? If I start Firefox normally with the error, I can't get to the add-ons at all. If I run in safe mode, the add-on screen doesn't let you re-enable them one at a time. Ideas?

All Replies (7)

more options

To ferret out the culprit you have to re-enable one addon at a time to see which one is problematic.

more options

But how? If I'm in safe mode, they're all disabled with no enable button.

more options

You should see an Enable button if you start Firefox in Safe mod without making changes on tha safe mode start window.

If it does work in Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears.

  • Use "Disable all add-ons" on the Safe mode start window to disable all extensions.
  • Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")
more options

I do run Safe mode without changes. On the add-on screen, there are "disable" buttons. I press those and they become "enable" buttons. But they are placebos. The add-ons do not enable. I guess Safe mode conquers all.

more options

If you see Enable buttons then you are not in Safe mode and the extensions are still enabled.

In Firefox 4+ versions you can use one of these to start in Safe mode:

  • Help > Restart with Add-ons Disabled
  • Hold down the Shift key while double clicking the Firefox desktop shortcut (Windows)
  • Don't make any changes on the Safe mode start window.
more options

Cor-el, I appreciate your quick responses.

I do restart using help-restart with add-ons disabled. (I'm on ver. 9.0.1) When it's finished, all add-ons *are* disabled. I then go to the add-on screen. At the top is a banner message, "All add-ons have been disabled by safe mode."

Some of the add-ons have "disable" buttons next to them. Pushing them merely switches the text in the button to "enable." Pushing again merely switches the text in the button to "disable." The title of each add-on never budges from "disabled." The banner message also remains unchanged.

So I cannot enable any of the add-ons while in safe mode.

more options

Fixed it! I think. I had to uncheck the boxes on the advanced java script window. Why, I don't know. But I think that did it.