Help Add-on InvientCharts

Hello
I try to use the Add-on InvientCharts but I find it difficult to romanticize.
I imported the project InvientChartsDemoApp demo, but it does not work
I have the following message

INFO: Requested resource not found from gold-through filesystem class loader. Add widgetset and / or theme JAR to your classpath or add files to WebContent / Vaadin folder.

and alert
Failed to load widgetset
InvientCharts /VAADIN/widgetsets/com.invient.vaadin.InvientChartsDemoAppWidgetset/com.invient.vaadin.InvientChartsDemoAppWidgetset.nocache.js?134567896531

Thank you for any help.
Sincerely,

I haven't used that project, but it sounds like you don't have a compiled widgetset. check out the Book of Vaadin on how to compile the widgetset.

you are right, this is the widgetset not well compiled.

thank you Jens Jansson