I am launching it from my dock, which I guess is a shortcut for the ArchiCAD21.app in "/Applications/GRAPHISOFT/ARCHICAD 21".
Just tried launching it using "open ARCHICAD\ 21.app" from that same directory, no more luck.
Thanks a lot, it works, I can now use the debugger correctly !
Though it is a bit annoying that i have to close / open ArchiCAD each time I want to make a change, it's wayyyy better than nothing.