write EINVAL error on Foreman for Heroku on Node.js, and on port 5000, immediately exited with code 8

问题

I'm new to Heroku and Foreman. Anyone know what the problem here is?

来源：https://stackoverflow.com/questions/24127434/write-einval-error-on-foreman-for-heroku-on-node-js-and-on-port-5000-immediate