ComponentRenderer for Grid-Cells doesn't create the Components

Hi everybody, 

I want to use the Addon ComponentRenderer: https://vaadin.com/directory#!addon/componentrenderer
It renders standard components in a Grid, so you can build a cell with a text and a picture in one Gridcell for example.
But all my tries are not working. I just get an empty Grid as result.
I am thankful for any help or advice. Thanks!

package view;

import java.util.ArrayList;

import com.vaadin.data.util.BeanItemContainer;
import com.vaadin.server.FontAwesome;
import com.vaadin.shared.ui.label.ContentMode;
import com.vaadin.ui.Component;
import com.vaadin.ui.Grid;
import com.vaadin.ui.Label;
import com.vaadin.ui.VerticalLayout;

import controller.TippappManager;
import entities.*;
import model.UserDaten;
import de.datenhahn.vaadin.componentrenderer.grid.ComponentGenerator;
import de.datenhahn.vaadin.componentrenderer.grid.ComponentGridDecorator;

public class ClassicGrid extends VerticalLayout {

    public ClassicGrid (TippappManager manager, UserDaten userDaten) {
        setSizeFull();
        setMargin(true);
        setSpacing(true);

        Grid grid = new Grid();
        grid.setContainerDataSource(new BeanItemContainer<Spiel>(Spiel.class));
        ComponentGridDecorator<Spiel> componentGridDecorator = new ComponentGridDecorator<>(grid, Spiel.class);
        
        int turnierID = userDaten.getUserTippgruppeByID(manager.getCurrentTippgruppe()).getTurnierId();
        ArrayList<Spiel> offeneSpiele = userDaten.getSpiele().get(turnierID);

        componentGridDecorator.addAll(offeneSpiele);

        grid.setSizeFull();
        grid.setEditorEnabled(true);
        grid.setEditorBuffered(false);

        ComponentGenerator<Spiel> generatorIcon = new ComponentGenerator<Spiel>() {
            @Override
            public Component getComponent(Spiel bean) {
                return new Label(FontAwesome.HOURGLASS_2.getHtml(), ContentMode.HTML);
            }
        };

        ComponentGenerator<Spiel> generatorText = new ComponentGenerator<Spiel>() {
            @Override
            public Component getComponent(Spiel bean) {
                return new Label(FontAwesome.HOURGLASS_2.getHtml(), ContentMode.HTML);
            }
        };

        componentGridDecorator.addComponentColumn("icon", generatorIcon);
        componentGridDecorator.addComponentColumn("text", generatorText);

        // always display the details column
        grid.setFrozenColumnCount(1);

        grid.setColumns( "icon", "text");

        addComponent(grid);
//        setExpandRatio(grid, 1.0f);
    }

}