Highstock + Highmaps not rendering

Question

I haven't been able to get my map to show any data; it just renders blank and in the console there's an error of "Uncaught TypeError: Cannot read property 'length' of undefined". I believe that the versions of Highstock and Highmaps that I use are compatible so I don't think that's the issue, however I could be wrong.

Click here for the fiddle

JS (geo_data is being fetched with AJAX)

$('#map').highcharts('Map', {
    title: {
        text: 'Installs Map'
    },
    colorAxis: {
        min: 0
    },
    series: [{
        data: geo_data,
        mapData: Highcharts.maps['custom/world'],
        joinBy: ['hc-key', 'country_id'],
        name: 'Installs',
        states: {
            hover: {
                color: '#BADA55'
            }
        }
    }],
    credits: {
        enabled: false
    }
});

Answer 1

Use the newest highstock master branch.

<script src="http://github.highcharts.com/highstock.js"></script>

http://jsfiddle.net/4a79s3qp/2/