Firefox and Multiple Profiles and Automator/AppleScript

I know exactly what the stderr redirect does. You don't need it, if you launch Firefox from the command-line like so:

open -a Firefox --args --ProfileManager

which has no resulting error message.

My guess would be a user access issue. When you run it in the Terminal, you are running that command as you. When run in Automator, it is run under the Automator user. Same for AppleScript,.

It may be as simple as giving Automator or AppleScript "Full Disk Access" in Security & Privacy System preferences.

The command-line throws that error message whether you select Exit, or Start Firefox from the ProfileManager dialog. This does not prevent Firefox from launching, and may be a side-effect of running it from within the application bundle. If you don't want to see that stderr message, then end the command with the following:

/Applications/Firefox.app/Contents/MacOS/firefox-bin --ProfileManager 2> /dev/null



The error also occurs with Firefox 76.0.1 on Mojave 10.14.6 (18G4032).