I cannot open Psychopy 2024.2.3 on macOS 14.6.1

Could you move these 2 files somewhere and restart the app, to see if that fixes it:
~/.psychopy3/appData.cfg
~/.psychopy3/userPrefs.cfg
(it can help if you go to your home folder and do Cmd-Shift-. to show hidden files)

Quite often the issue is a corrupt prefs/config file