vaadin example visual designer

I follow steps:

  1. http://demo.vaadin.com/sampler-for-vaadin6#MenuBarWithIcons in chrome
  2. download the war file of this example
  3. import it to eclipse
  4. navigate to this file
  5. right click this file and open it with vaadin designer
    it will throw error. I attached two pictures, and it shows the error.

How can I open this file and have a visual designer and make some change of it?

Thanks for reply
13083.jpg
13084.jpg

Please see a discussion about this issue
here
.