Neil1955 wrote:

All existing solutions speak to 'Open Profile Manager'...there is no such program on a Mac.

The profile manager is a Firefox feature, not a separate program.

1. Quit Firefox.
2. Open Terminal from Applications/Utilities.
3. Enter the following command, then press the Return key:

/Applications/Firefox.app/Contents/MacOS/firefox-bin -p

For additional details, see

• Profile Manager - Create, remove or switch Firefox profiles

I've tried the Terminal action many times and same error message pops up. The next section 'For additional details, see "Use the Profile Manager to create and remove Firefox profiles does not refer to Macs...it speaks to 32-bit and 64-bit windows.

Please,, please can a Mozilla / Firefox technician intervene?

1. Click the Finder icon in the dock.
2. On the menu bar, click the Go menu, hold down the option or alt key and select Library. A window will open containing your Library folder.
3. Open the "Application Support" folder, then open the "Firefox" folder.
4. Rename the profiles.ini file to profiles.ini-old
5. The next time you start Firefox, it should start with a brand new profile. See the following article for directions on recovering data from your old profile.
   • Recovering important data from an old profile

Neil1955 wrote:

The next section 'For additional details, see "Use the Profile Manager to create and remove Firefox profiles does not refer to Macs...it speaks to 32-bit and 64-bit windows. 

Provided that JavaScript and cookies are enabled in your browser, support articles will show you information relevant to your operating system. You can also click the Editing Tools section on the left and choose to see information for a different operating system or version of Firefox.

I have tried everything and there is no profiles.ini file anywhere on my Mac. There is also no Profile Manager program. I have used Terminal to enter commands as directed and 'profile missing message still appears.' Apple Care cannot help.