Greeting, I'm working on a javafx program using a list view to display different movies but I get an error if I run the program, mind helping?

Code: package javaapplication3;

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Orientation;
import javafx.scene.Scene;
import javafx.scene.control.ListView;
import javafx.scene.control.SelectionMode;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.media.Media;
import javafx.scene.media.MediaPlayer;
import javafx.scene.media.MediaView;
import javafx.stage.Stage;

public class MoviePlayer extends Application {
@Override
public void start(Stage primaryStage) {
Pane pane = new Pane();
HBox hb = new HBox();

ListView list = new ListView();
list.getItems().addAll("ToyStory", "Frozen", "Mulan");
list.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
list.setPrefSize(140, 250);
list.setOrientation(Orientation.VERTICAL);

Media movie1 = new Media("javaapplication3/ToyStory.mp4");
Media movie2 = new Media("javaapplication3/Frozen.mp4");
Media movie3 = new Media("javaapplication3/Mulan.mp4");

MediaPlayer mp1 = new MediaPlayer(movie1);
MediaPlayer mp2 = new MediaPlayer(movie2);
MediaPlayer mp3 = new MediaPlayer(movie3);

MediaView mv = new MediaView(mp1);
mv.setFitHeight(400);
mv.setFitWidth(500);

hb.setPadding(new Insets(2,2,0,0));
hb.getChildren().addAll(list,mv);
pane.getChildren().addAll(hb);


list.setOnMouseClicked(e->{
String value = list.getSelectionModel().getSelectedItem().toString();
if(value.equals("ToyStory")){
mv.setMediaPlayer(mp1);
mp1.play();
mp2.pause();
mp3.pause();
}
if(value.equals("Mulan")){
mv.setMediaPlayer(mp2);
mp2.play();
mp1.pause();
mp3.pause();
}

if(value.equals("Frozen")){
mv.setMediaPlayer(mp3);
mp3.play();
mp2.pause();
mp1.pause();
}
});


Scene scene = new Scene(pane,650,300);
primaryStage.setScene(scene);
primaryStage.setTitle("Movie Viewer");
primaryStage.show();



}
public static void main(String[] args) {
launch(args);
}
}
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Error Message Attached Below: