Grails: Getting the Vaadin plugin to run. "Can not process requests before init() has been called"

I had the problem after I installed the grails-vaadin plugin when starting my application I would get the following error

There is a bug in the GrailsVaadinServlet where you have to add the service.init() call.

 

Fortunately when you install the plugin you edit the source code as it is downloaded to your grails project. Mine was found here: