Strange socket.io.js error on client side

I'm getting these strange error during my attempts to get socket.io working.

Also, my socket.io.js file appears like this in chrome:

I know my socket.io.js file does not have this within it.

My client code is as follow:

// Set up sockets
var socket = io.connect();

socket.on('statusMessage', function(data){
    console.log(data.message);
});

My server code is as follows

var serv_io = io.listen(server);
serv_io.sockets.on('connection', function(socket){
    socket.emit('statusMessage', {'message': 'Succesfully connected to serve via   sockets'});
});

I am also requiring socket.io in a simple way:

var io = require('socket.io');

I am also deploying on Heroku.

Why is this happening?