Thanks for the quick response. Yes, I have Firefox in my Application folder. When I double click on the app icon to launch or right click to open Firefox, it blinks and nothing else happens. I ran the Disk Utility scan and typed the command in terminal mode and no changes. I called apple...
I have read the forum and am not a Mac Expert. I am not sure where a couple of suggested locations are to be found to follow the fixes.
Open the Terminal application, and type "open -a Firefox" at the prompt, then
hit Enter. Do you get any error messages? Where is the terminal application?