Callback was already called error is shown on running the code

[paik1]

On executing the below code i get "Callback was already called" error even after the commanfd gets executed.Can someone help me with some solution as I am new to node

var rexec = require('remote-exec');

var connection_options = {
port: 22,
username: 'username',
password: 'password'
};

var hosts = [
'host ip'
];

var cmds = [
'more Documents\SSH.txt'
];

rexec(hosts, cmds, connection_options, function(err){
if (err) {
console.log(err);
} else {
console.log('Great Success!!');
}
});