Hello (Bonjour) !
Installation : ok
Launch : ok (right click and open)
Usage: impossible to graphically connect objects, messages, etc...
except with connect selection (command K) which does not manage the connected point

an idea ?
thanks in advance

@ReneP
rookie mistake : just hold down mouse or pad to make the connections.....

Catalina problem to solve Cannot open "xxx" because this app is from an unidentified developer"
with Gem.pd_darwin for example