OK, I’ve found another possible cause of crashes on macos depending on how you shut down. If you closed all the windows before closing the app (which some people do if they come from Windows where closing the window and closing the app are synonymous) then PsychoPy stores the last open window as “None”. That then confuses PsychoPy when you next open because it tries to get the views back to the previous state and there is none.
This will be an easy one to fix now I’ve found it but, in the meantime, you can:
edit your file ~/.psychopy3/appData.cfg to include
lastFrame = builder
and then make sure you close the app by Cmd-Q rather than closing the windows