Vaadin Spring integration

Hi,
I use official spring addon for Spring Vaadin integration. Here is the code:

@Theme("valo")
@SpringUI
public class App extends UI {

    @Override
    protected void init(VaadinRequest vaadinRequest) {
    }

    public static void main(String[] args) throws Exception {
        AnnotationConfigWebApplicationContext webApplicationContext = new AnnotationConfigWebApplicationContext();
        webApplicationContext.register(AppConfig.class);

        Server webServer = new Server(8080);
        ServletContextHandler servletContextHandler = new ServletContextHandler(webServer, "/", true, true);
        servletContextHandler.addServlet(new ServletHolder(new SpringVaadinServlet()), "/");
        //servletContextHandler.addServlet(new ServletHolder(new VaadinServlet()), "/*");
        servletContextHandler.setInitParameter("UI", "App");
        servletContextHandler.addEventListener(new ContextLoaderListener(webApplicationContext));
        webServer.start();
        webServer.join();
    }

}

But after the start of the application I get:

Problem accessing /.
Reason:Request was not handled by any registered handler.
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VaadinServlet is working properly.