I'm trying to set up OSC communication between chuck and python-osc. It appears that the messages we send from the python side do not arrive at the chuck side. All other combinations, i.e. python to python, chuck to chuck and chuck to python are working fine though. I'm running python 3.4.4 on windows 7. What could be going wrong here? Here are the four files with the client/server implementations I'm using for testing. ### chuck_client.py: OscSend xmit; xmit.setHost("localhost", 5005); <<<"Sending">>>; xmit.startMsg("/debug"); ### chuck_server.py: OscRecv orec; 5005 => orec.port; orec.listen(); orec.event("/debug") @=> OscEvent e; <<<"Waiting">>>; e => now; <<<"Received">>>; ### python_client.py: from pythonosc import osc_message_builder from pythonosc import udp_client client = udp_client.UDPClient('localhost', 5005) msg = osc_message_builder.OscMessageBuilder(address="/debug") msg = msg.build() print('Sending') client.send(msg) ### python_server.py: from pythonosc import dispatcher from pythonosc import osc_server dispatcher = dispatcher.Dispatcher() dispatcher.map("/debug", lambda _: print('Received')) print('Waiting') server = osc_server.ThreadingOSCUDPServer( ('localhost', 5005), dispatcher) print("Serving on {}".format(server.server_address)) server.serve_forever() This issue can also be viewed on github: https://github.com/ccrma/chuck/issues/54#issuecomment-213495106