"n is not a constructor"

[Holly]

I am using version 2019.1.220 with Kendo UI for ASP.NET MVC, having upgraded recently from 2016.1.112, and I am now getting a Javascript error: "n is not a constructor". My chart is fairly simple:

@(Html.Kendo().Chart(Model.Errors)
    .Name("AppErrorsChart")
    .Title("Error BreakDown By % Frequency?")
    .Legend(legend => legend
        .Position(ChartLegendPosition.Top)
    )
    .Series(series =>
    {
        series.Pie<int>(model => model.Count, model => model.Type)
        .Labels(labels => labels
            .Visible(true)
            .Template("#= category # - #= kendo.format('{0:P}', percentage)#")
        );
    })
    .Tooltip(tooltip => tooltip.Visible(true).Template("#= dataItem.Error# (#= value#)").Color("#FFF"))
    .Events(e => e.SeriesClick("onCategorySeriesClick").AxisLabelClick("onCategorySeriesClick")
    )
)

[Tsvetina]

Hello Howard,

The problem is specifically in having a reference to kendo.web.min.js. When there is a kendo.all.min.js reference, all Kendo UI widgets are already included in the page and you should not reference subsets of the Kendo UI library (web, dataviz, etc.).

In this scenario, when kendo.web.min.js is referenced after kendo.all.min.js, it overwrites the plugins registered by the "all" file and widgets that are not part of the "web" subset, including the Chart, cannot be loaded. You can see in the Dojo that if you remove the "web" reference, the Chart loads successfully.

Regards,
Tsvetina
Progress Telerik

[Holly]

Great, thank you so much. We had the references to both when using the 2016 version and it did not cause any problems, so there was no reason for us to think any different this time.