Unable to load the chart
Unable to load the chart of class
Can you double-check your code and make sure
assets/js/widgets.bundle.js is included in your page? The widget you refer to used
core/HTML/src/js/widgets/charts/widget-19.js source code and during the gulp or webpack build it will be bundled in the above bundle js script.
If you need any further help please let me know how are you going to load the above chart.