Eu criei um aplicativo usando o jfxPanel dentro do componente swing. O problema que estou enfrentando é que não estou conseguindo alterar os arquivos fxml. Quando um botão do fxml é clicado, desejo descartar esse fxml e carregar outro arquivo fxml lá. Isto é o que eu fiz até agora

public class NonResponsiveButtons extends JFrame {
    NonResponsiveButtons nrb;
    BottomPanelIncomingController bpic;
    JPanel panel; 
    JPanel bPanel;

    private int applicationWidth_600 = 600;
    private int applicationHeight_600 = 600;

    private int upperPanelHeight_535 = 535;
    private int bottomPanelHeight_65 = (applicationHeight_600-upperPanelHeight_535); 


    public static void main(String[] args) {
    new NonResponsiveButtons();
    }



    public NonResponsiveButtons(){
        final JFXPanel fxPanel = new JFXPanel();

        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
            // TODO Auto-generated method stub
                try{
                    new JFXPanel();
                    add(getJPanel(), BorderLayout.CENTER);
                    add(getJBottomPanel(), BorderLayout.PAGE_END);
                    bPanel.add(fxPanel, BorderLayout.CENTER);

                    Platform.runLater((new Runnable() {

                    @Override
                    public void run() {
                        // TODO Auto-generated method stub
                        initFX(fxPanel);    
                    }
                })) ;

            }
                catch(Exception e){
                    System.out.println("Error in swing utilities thread :" + e.getMessage());
            }

        }
    });

    this.setSize(applicationWidth_600, applicationHeight_600);
    setLocationRelativeTo(null);
    BorderLayout borderLayout = new BorderLayout();
    setLayout(borderLayout);

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     
    setVisible(true);
}


private void initFX(JFXPanel jfxPanel) {
    try {
        FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("fxmlDesign.fxml"));
        Parent root = (Parent) fxmlLoader.load();
        Scene scene = new Scene(root, 600, 65);
        jfxPanel.setScene(scene);

        fxmlLoader.getController();
        bpic = new BottomPanelIncomingController();
        bpic.setNonResoinsiveButtons(this);

    } catch (IOException exc) {
        exc.printStackTrace();
        System.exit(1);
    }
}

public void loadSecondFxml(){
    System.out.println("loading second fxml");
}   

private JPanel getJPanel(){
    if(panel == null){
    panel = new JPanel();
    panel.setSize(applicationWidth_600,upperPanelHeight_535);
    panel.setBackground(Color.gray);
    }
    return panel;
}

private JPanel getJBottomPanel(){
    if(bPanel == null){
        bPanel = new JPanel();
        bPanel.setSize(applicationWidth_600, bottomPanelHeight_65);
        bPanel.setBackground(new Color(8, 16, 19));
    }
    return bPanel;
}   

}

A classe BottomPanelIncommingController. O controlador fxml

public class BottomPanelIncomingController implements Initializable {
 NonResponsiveButtons nrb;

    @Override
    public void initialize(URL arg0, ResourceBundle arg1) {
    // TODO Auto-generated method stub
    System.out.println("HEllo");
    }

    public void setNonResoinsiveButtons(NonResponsiveButtons nrb){
    this.nrb = nrb;
    }

    @FXML
    public void callAccepted(ActionEvent event){
    System.out.println("From controller");
    nrb.loadSecondFxml();
    }
 }