[Solved]-Zoom in not working on Highmaps-Highcharts

This must be a bug, it works if you change your coordinate data. jsFiddle:

var geoJson = {
    "type": "FeatureCollection",
        "features": [{
        "type": "Feature",
        "properties": {
            "name": "a"
        },
            "geometry": {
            "type": "Polygon",
                "coordinates": [
                [
                    [3125, 6250],
                    [5625, 6250],
                    [5624, 8750],
                    [3125, 8750],
                    [3125, 6250]
                ]
            ]
        }
    }, {
        "type": "Feature",
            "properties": {
            "name": "b"
        },
            "geometry": {
            "type": "Polygon",
                "coordinates": [
                [
                    [6875, 6250],
                    [9375, 6250],
                    [9375, 8750],
                    [6875, 8750],
                    [6875, 6250]
                ]
            ]
        }
    }]
};

// Initiate the chart
$('#container').highcharts('Map', {

    mapNavigation: {
        enabled: true,
    },

    series: [{
        mapData: geoJson
    }]
});

I suggest filing an issue on GitHub, and we'll look into it in detail.