java.lang.reflect.InvocationTargetException, получая в showAndWait

Question

Я создаю диалоговое окно, но dialog.showAndWait вызывает ошибки

"Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException"

эта ошибка появляется.

Главный класс:

  @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Favori Filmlerim");
        primaryStage.setScene(new Scene(root, 900, 600));
        primaryStage.show();
    }

Класс контроллера:

 package sample;


import javafx.application.Platform;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.control.ButtonType;
import javafx.scene.control.Dialog;
import javafx.scene.layout.BorderPane;

import java.io.IOException;
import java.util.Optional;

public class Controller {

    @FXML
    private BorderPane anaPencere;

    @FXML
    void filmEkleDialog(ActionEvent event) throws IOException {
        Dialog<ButtonType> dialog = new Dialog<>();
        dialog.initOwner(anaPencere.getScene().getWindow());

        FXMLLoader fxmlLoader = new FXMLLoader();
        fxmlLoader.setLocation(getClass().getResource("yeniFilmDialog.fxml"));

        dialog.setTitle("Yeni Film Ekle");
        dialog.getDialogPane().setContent(fxmlLoader.load());

        dialog.getDialogPane().getButtonTypes().add(ButtonType.APPLY);
        dialog.getDialogPane().getButtonTypes().add(ButtonType.CANCEL);

        Optional<ButtonType> sonuc = dialog.showAndWait();

        if (sonuc.get() == ButtonType.APPLY){
            YeniFilmDialog dialogController = fxmlLoader.getController();
            dialogController.yeniNotuEkle();
        }
    }

    @FXML
    void uygulamayiKapat(ActionEvent event) {
        Platform.exit();
    }

}