Hi @Jan Wagenaar 

A couple of things:

1. you can't have block instances from both Charts versions on the same screen. 
2. you need to make sure the script you're importing using HighchartsModules comes first on your widget tree so it gets loaded first
3. HighchartsModules block is only available for the new Charts version, not for v1

Something like this: 

To achieve what you want without exploring all the extensibility actions (that would be the best way and the one that the product will always support) you can add the following Js Node to the initialize event handler:

const chartXrange = {
    chart: {
        type: 'xrange'
    },
    title: {
        text: 'Highcharts X-range'
    },
    accessibility: {
        point: {
            descriptionFormat: '{add index 1}. {yCategory}, {x:%A %e %B %Y} to {x2:%A %e %B %Y}.'
        }
    },
    xAxis: {
        type: 'datetime'
    },
    yAxis: {
        title: {
            text: ''
        },
        categories: ['Prototyping', 'Development', 'Testing'],
        reversed: true
    },
    series: [{
        name: 'Project 1',
        borderColor: 'gray',
        pointWidth: 20,
        dataLabels: {
            enabled: true
        }
    }]
}

OutSystems.ChartAPI.Chart.GetById($parameters.ChartWidgetId).provider.update(chartXrange, true, true);

Here's the result (ofc it needs some fine-tunning but you'll get the idea):

Hope it helps.

Cheers,
GM