This happens when there is a profiles.ini file, but the default profiles listed in this file is missing.

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

You can use the Profile Manager to create a new profile.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile (in case there is still one) to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

I'm sorry but this does not solve my issue.

There is No profile folder for the profile.ini. The ~/Library/Application Support/ folder does not contain Mozilla or Firefox.

Also, when I attempt to run the Profile Manager using the following command: /Applications/Firefox.app/Contents/MacOS/firefox -profilemanager

I still get the same error or Profile missing or inaccessible.

Note that the ~/Library is a hidden folder.

If you also get this error when you try to launch the Profile Manager via a terminal window then that would indicate that Firefox is running some how and you may need to check that in the process monitor or reboot the computer.

• http://kb.mozillazine.org/Kill_application
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Thank you. I was unable to find Firefox in the Process Monitor or in the Activity Monitor. But a reboot fixed the issue.

You're welcome