Firefox 4.0.1 giving "TypeError: Components.classes[cid] is undefined". How can I fix this? Other posts on this issue have not solved my problem.
I've started Firefox in Safe Mode with no addons, extensions, or themes enabled. And it still happens. I've noticed Greasemonkey is installed but can find no way to remove it - but no scripts are installed in it.
I am running AVG antivirus and have read the web-protection component could be causing this problem but have not read how to correct it. Any info would be greatly appreciated.
Happens every time I open Firefox for the first times and every time I open a new browser window. Also happens anytime a web page spawns a popup window. Does NOT happen when I just open a new tab or a link into a new tab.
Vald lösning
Do a clean (re-)install:
- Download a fresh Firefox copy and save the file to the desktop.
- Firefox 4.0.x: http://www.mozilla.com/en-US/firefox/all.html
- Uninstall your current Firefox version and remove the Firefox program folder before installing that copy of the Firefox installer.
- Do not remove personal data if you uninstall the current version.
- 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.
- It may not be necessary to create a new profile, so first try if it works with your current profile and if not then create a new profile.
Create a new profile as a test to check if your current profile is causing the problems. See:
There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins"
If that new profile works then you can transfer some files from the old profile to that new profile (be careful not to copy corrupted files)
See:
Läs svaret i sitt sammanhang 👍 3Alla svar (5)
Vald lösning
Do a clean (re-)install:
- Download a fresh Firefox copy and save the file to the desktop.
- Firefox 4.0.x: http://www.mozilla.com/en-US/firefox/all.html
- Uninstall your current Firefox version and remove the Firefox program folder before installing that copy of the Firefox installer.
- Do not remove personal data if you uninstall the current version.
- 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.
- It may not be necessary to create a new profile, so first try if it works with your current profile and if not then create a new profile.
Create a new profile as a test to check if your current profile is causing the problems. See:
There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins"
If that new profile works then you can transfer some files from the old profile to that new profile (be careful not to copy corrupted files)
See:
Didn't actually have to do the uninstall/reinstall. Just created a new profile and transferred bookmarks/passwords. I notice now that Greasemonkey no longer shows up. And no more error messages for new windows.
I also reactivated all of AVG antivirus's online scanning tools and everything is still fine.
Thanks for the tip!
how do you create a new profile?
See my above post [*]
I solved this problem by deleting the file "{35379F86-8CCB-4724-AE33-4278DE266C70}" on the "extension" folder located at the backup folder of the history and bookmarks of mozilla.