Uncaught Error: Error: An invalid exception was thrown

I am trying to use ExternalInterface to call a Flash Function from javascript.

My JS:

function thisMovie(movieName) {
if (navigator.appName.indexOf("Microsoft") != -1) {
    return window[movieName]
}
else {
    return document[movieName]
}
}

function DoThis() {
$.ajax({
    url: 'POSTINGURLHERE',
    type: 'POST',
    dataType: 'json',
    data: { 'at': 1 },
    success: function(result) {
        thisMovie("ID").Lol(result['xD']);
    }
});
}

This code works perfectly on Localhost, just not on my public webhost? I am getting on Google Dev Tools: http://ift.tt/1IDt7fE

I have the flash callbacks set in the swf, perfect for Localhost as mentioned. So why is it not working on my webhost?