[emerg]: bind() to 0.0.0.0:80 failed (98: Address already in use)

nginxCP can fail to start because another service is using Port 80, thus preventing nginxCP from starting. Often an error similar to the below will be thrown out –

[emerg]: bind() to 0.0.0.0:80 failed (98: Address already in use)

You can kill the process on Port 80 by running the following in the terminal –

sudo fuser -k 80/tcp

Then, you can simply start nginxcp again

service nginx start