mac Port 4200 is already in use. code example
Example 1: Port 4200 is already in use. Use '--port' to specify a different port
sudo lsof -t -i tcp:4200 | xargs kill -9
Example 2: port 4200 is already in use.
netstat -a -n -o
sudo lsof -t -i tcp:4200 | xargs kill -9
netstat -a -n -o