Browser will not start up

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Revision as of 12:55, 4 April 2005; view current revision
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Template:Test File names and program names are different for Mozilla Suite.

If Firefox used to work correctly, but it no longer starts when you try to run it, then this article may help. Before deleting anything, please back up your profile.


The Profile In Use bug

If you receive the "profile is in use" error when trying to launch the application, this means the profile is locked. See the Profile in use article for instructions on fixing this.

How to make Firefox/Mozilla Suite start

  1. Completely close the application (using "File -> Exit") and make sure Firefox is not running in the backround.
  2. Firefox only. Run Firefox in safe mode. If it starts up in safe mode, the problem is most probably with one of your themes or extensions. Select the default theme in "Tools -> Themes" and disable all your extensions in "Tools -> Extensions". Restart Firefox.
  3. Before continuing, be sure to back up your profile.
  4. Delete "XUL.mfl" (the name may differ slightly, e.g. "xul.mfasl") from your profile folder. This file will be regenerated on next startup. Try running Firefox now.
  5. Delete "chrome" and "extensions" folders from your profile. (You will lose all your extensions and themes!)
  6. Delete the "Cache" folder. (You will lose your cache.)
  7. If application still does not work, it is usually best to create a new profile.
  8. If it still doesn't work, try reinstalling the application. Remember to uninstall the application first.

The Mac Firefox bug

From Firefox 1.0.2 Release Notes:

If Firefox does not display a browser window, quit Firefox using Cmd+Q and open ~/Library/Application Support/Firefox/Profiles/<garble>.default/ and remove "localstore.rdf". Restart Firefox. Any toolbar customizations you have made or window placement will be lost

Firefox starts but my settings are gone

  • Make sure you're using the correct profile. Run the Profile Manager and select the default profile.
  • If that wasn't your problem and you have backed up your profile, you should be able to simply copy the backed up files to your new profile. See "What do I do if my profile's corrupted?" for help on doing this.
  • If you are missing themes or extensions, you will have to reinstall them from scratch.