Error while opening design view

Hi all

I need some help regarding the error I get when I try to open one of the forms generated by the Vaadin plugin for Roo described here
Spring Roo with Vaadin
(see my comment at the bottom of the article)

Is that fixable or am I supposed to use a certain version of Eclipse/STS?

One of the generated classes has the following signature:

@RooVaadinVisuallyComposableEntityForm(formBackingObject =
public class PizzaForm extends CustomComponent implements EntityEditor {

According to [quote]
The visual editor works with custom component classes that extend the CustomComponent class
[/quote] that should work.

Any pointers on that?