Why this error occurs ? how can we avoid it ?
its because your are trying run a server using the port number which is being used already for e.g suppose server abc is running alreay on port 5005 and you are trying to run server def using the same port so the above issue occurs,you can avoid it bybusing unqiue port for each server you are running
how can we change port number ? in which file we have to make changes
you can change it in your server configuration
Such useless advice!