Firefox does not open, but instead gives the error message, "Failed to read the configuration file." It has worked in the past, but not now.
We recently uninstalled a proxy website's filtering program. Now, Firefox will not open, but instead, gives the error message, "Failed to read the configuration file. Please contact your system administrator." I've reinstalled it with a reboot between uninstalling and reinstalling. That didn't work. I installed a previous version, that didn't work. Finally, I reinstalled it without keeping any of my settings and bookmarks and it still doesn't work. I've checked my firewall and it's in the exceptions. Deleted that and replaced it. All to no avail. Still scratching my head.
Chosen solution
You get that error if a mozilla.cfg file is specified, but can't be processed or isn't found.
So it must at least be specified to get that error.
Try to delete the Firefox program folder before reinstalling Firefox to be sure that all files are removed.
Download a fresh Firefox copy and save the file to the desktop.
- Firefox 9.0.x: http://www.mozilla.org/en-US/firefox/all.html
Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.
- It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
- http://kb.mozillazine.org/Uninstalling_Firefox
Your bookmarks and other profile data are stored elsewhere in the Firefox Profile Folder and won't be affected by a reinstall, but make sure that you do not select to remove personal data if you uninstall Firefox.
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All Replies (6)
Hi,
Please check if there's a mozilla.cfg file in the Firefox installation folder and rename or delete it, if present.
...............................................................................................................................
Useful links:
Going beyond Tools > Options - about:config
Page Info Tools (Alt + T) > Page Info, Right-click > View Page Info
Firefox Profile Folder & Files
Deleting mozilla.cfg won't help. You need to remove the file that specifies to use mozilla.cfg. That is probably a file in the defaults\pref folder (C:\Program Files\Mozilla Firefox\defaults\pref)
co-rel is right, the file to be renamed / deleted is local-settings.js file, if present in the \defaults\pref folder which points to mozilla.cfg.
Modified by Vivek
Thanks guys, but neither of these files exist.
Chosen Solution
You get that error if a mozilla.cfg file is specified, but can't be processed or isn't found.
So it must at least be specified to get that error.
Try to delete the Firefox program folder before reinstalling Firefox to be sure that all files are removed.
Download a fresh Firefox copy and save the file to the desktop.
- Firefox 9.0.x: http://www.mozilla.org/en-US/firefox/all.html
Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.
- It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
- http://kb.mozillazine.org/Uninstalling_Firefox
Your bookmarks and other profile data are stored elsewhere in the Firefox Profile Folder and won't be affected by a reinstall, but make sure that you do not select to remove personal data if you uninstall Firefox.
Modified by cor-el
Jalapeno! Finally. Something that works. I never thought to check to see if the folder was still there after uninstalling or that there may be hidden files left behind.
Thanks Cor-el