JavaFX 2.0 Toolbar FXML

Question

Q: Help me identify what's causing the error, and hopefully getting the toolbar to work.

I'm trying to take the FXML-version from this page: Difference in my java-class from link1:

1. It's not a main-class.
2. It does not extend Application but HBox or anything if it would work.
3. Error message: "javafx.fxml.LoadException: javafx.fxml.JavaFXBuilder$ObjectBuilder does not have a default property."

4. Well, here the class is:

   public class MainWindow implements Initializable { private ResourceBundle rb;

   final static boolean RIGHT_TO_LEFT = false;
   
      //FXML ATTRIBUTES
       @FXML
       private OverviewTab owContent;
       @FXML
       private StatisticsTab statisticsContent;
       @FXML
       private SettingsTab settingsContent;
       @FXML
       private Polygon dock_bottom;
       @FXML
       private TabPane tabpane; 
       @FXML
       private Tab owTab;
       @FXML
       private Tab statisticsTab;
       @FXML
       private Tab settingsTab;
       @FXML
       private Button helpButton;
       @FXML
       private Button updateButton;
       @FXML private Button task;
   
   
   /**
    * Create the application.
    */
    @Override
       public void initialize(URL url, ResourceBundle rb) {
        this.rb = rb;
           // Adding Swing style of custom Listener
           tabpane.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<Tab>() {
               @Override public void changed(ObservableValue<? extends Tab> observableValue, Tab oldTab, Tab newTab) {
                   if(newTab.equals(owTab)){
   
                   }
               }
             });
        //statisticsContent.addListener(this);
       owTab.setText(rb.getString("overviewTab_headline"));
       statisticsTab.setText(rb.getString("statisticsTab_headline"));
       settingsTab.setText(rb.getString("settingsTab_headline"));
    }
   

   }

Answer 1

The author of the tutorial you are referencing, mentions the error and provides solution to it in his next post/tutorial. See ToolBar in FXML No Longer Requires tag. I think you are facing the same problem.