Please try following the steps mentioned in Profile Manager - Create, remove or switch Firefox profiles to create a new Firefox profile that should fix this issue.

Try to delete the profiles.ini file to force Firefox to create a new default profile.

• http://kb.mozillazine.org/profiles.ini_file
• http://kb.mozillazine.org/Profile_folder_-_Firefox

• https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Are you using Firefox for Android?

Thank you everyone. Deleting the profile cleared the problem. For those on a Mac here is how I did it after searching the Mozilla help files (and a little extra help from some kind users): Open Finder Open Go Hold down Option (alt) to bring up Library Go to Firefox and open application Look for profile ini. Delete profile. Firefox will restart as if you were a new user and ask if you want to import from another browser. In my case I imported what I had in Safari for bookmarks, etc. Up and running again OK

have this problem....so frustrating...nothing posted on this site or anywhere else works. I've deleted Firefox several times, reinstalled..nothing. Firefox won't even open a window so I can use some of the advice posted, such as reseting to default settings. Delting everything, including the profile.ini int the library which is in the Library, only accessible by holding the "alt" key in the latest version of Mac (who thought this one up, aaaargh!!!) did not work either. I have no idea what brought this on. I spent memorial day on vacation at Marriott Hotel in Denver. that is the only thing I've done different since this problem started. I've had to switch to Chrome and Safari. I've been a faithful user of Firefox for over a decade. It has the greatest web design tools, search capabilities. I type one letter of a favorite site and it pops open. I'm so sad to leave your browser, but I have no choice. But absolutely othing is working!!!!

I have deleted everything related to Firefox in Application Support. Removed the firefox plist in the Preferences. Used AppZapper to supposedly delete all Firefox related files. Reset permissions using : sudo chown -R `id -un`:`id -gn` ~

I am on an older Mac but it is running 10.8.4

I have used Firefox for years as Firebug is essential to my work. I have been playing with the Chrome Dev tools recently and I guess this means I will have to commit to Chrome now unless someone can really fix this. I need to be able to work. When Firefox starts to lose the developers then....

Hello firebobby, when you re-install firefox, open a Terminal window and type the next command to see IF we can create a new test profile :

/Applications/Firefox.app/Contents/MacOS/firefox -CreateProfile test

OR

/Applications/Firefox.app/Contents/MacOS/firefox-bin -CreateProfile test

any luck ?

thank you