I just took a closer look at your screenshot. It’s Iannix itself that would seem to be competing with Max! You have Iannix also listening on port 2001. I think you want to reverse, in Iannix, those ports 1234 and 2001. Then you should be good to go.
A workaround would be to change the port number in both places: IanniX and Max. But my inclination is to get to the bottom of this.
So, let’s snoop around and get the rundown on open sockets:
Open a terminal:
sudo lsof -i -P
If you want to see only processes associated with that particular port:
sudo lsof -i -P | grep "2001"
If you want to create a file to attach so we can see the output too, you might do this:
sudo lsof -i -P > MyPorts.txt
sudo lsof -i -P | grep "2001" > MyPorts.txt
… there is probably something already bound to this port.
I tried to change this one but nothing happens (always the same message in the Max Window)