title: Why "java.lang.reflect.InvocationTargetException" showing
body: <p>I am developing a project in <code>javafx</code> using <code>NetBeans IDE</code>. Whenever I run my code I am getting some exceptions. There was no problems till yesterday. The exceptions are given below :</p>
  
  <pre><code>Executing E:\Project\WelcomePage\dist\run204992192\WelcomePage.jar using platform       C:\Program Files\Java\jdk1.7.0_45\jre/bin/java
  Exception in Application constructor
  java.lang.reflect.InvocationTargetException
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:606)
  at com.javafx.main.Main.launchApp(Main.java:698)
  at com.javafx.main.Main.main(Main.java:871)
  Caused by: java.lang.RuntimeException: Unable to construct Application instance: class welcomepage.WelcomePage
      at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:393)
      at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:47)
      at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:115)
      at java.lang.Thread.run(Thread.java:744)
      Caused by: java.lang.NoSuchMethodException: welcomepage.WelcomePage.&lt;init&gt;()
      at java.lang.Class.getConstructor0(Class.java:2810)
      at java.lang.Class.getConstructor(Class.java:1718)
      at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:275)
      ... 3 more
      Java Result: 1
  </code></pre>
  
  <p>My source code is very large, so I excluded the import statements. I will provide a part of my code below:</p>
  
  <pre><code> class WelcomePage extends Application {
   @Override
   public void start(Stage stage33) {
  
      BorderPane border = new BorderPane();
  
      border.setTop(addVBox());
      border.setLeft(addVBox1());
  
      Scene scene = new Scene(border,700,450);
      stage33.setScene(scene);
      stage33.setResizable(false);
      scene.getStylesheets().add
      (WelcomePage.class.getResource("WelcomePage.css").toExternalForm());
      stage33.show();
  
   }
  
   private VBox addVBox() {
  
      VBox vbox = new VBox();
      vbox.setPadding(new Insets(5, 12, 5, 20));
      vbox.setSpacing(10);   // Gap between nodes
      //vbox.setStyle("-fx-background-color: #999999;");
  
      Image image = new Image(getClass().getResourceAsStream("logo11.png"));
      Label lb1=new Label("    C - MARK AND ATTENDANCE CALCULATOR");
      lb1.setAlignment(Pos.CENTER);
      lb1.setFont(Font.font("Calibri",FontWeight.BOLD,28));
      lb1.setTextFill(Color.BLACK);
      lb1.setGraphic(new ImageView(image));
  
      vbox.getChildren().addAll(lb1);
  
      return vbox;
   }
  
   private VBox addVBox1()
   {
      VBox vbox1=new VBox();
      vbox1.setPadding(new Insets(20, 2, 15, 20));
      vbox1.setSpacing(20);
  
      Button btnl2=new Button("SIGN IN");
      btnl2.setFont(Font.font("Calibri",FontWeight.BOLD,16));
      btnl2.setPrefSize(300,60);
      btnl2.setStyle(" -fx-base: #0066cc;");
  
      btnl2.setOnAction(new EventHandler&lt;ActionEvent&gt;() {
       @Override
       public void handle(ActionEvent e) {
         signin();
       }
       });
  
      Button btnl4=new Button("HELP");
      btnl4.setFont(Font.font("Calibri",FontWeight.BOLD,16));
      btnl4.setPrefSize(300,60);
      btnl4.setStyle(" -fx-base: #0066cc;");
  
      btnl4.setOnAction(new EventHandler&lt;ActionEvent&gt;() {
       @Override
       public void handle(ActionEvent e) {
        help();
       }
       });
  
      Button btnl5=new Button("ABOUT");
      btnl5.setFont(Font.font("Calibri",FontWeight.BOLD,16));
      btnl5.setPrefSize(300,60);
      btnl5.setStyle(" -fx-base: #0066cc;");
  
      btnl5.setOnAction(new EventHandler&lt;ActionEvent&gt;() {
       @Override
       public void handle(ActionEvent e) {
        about();
       }
       });
  
      Button btnl6=new Button("EXIT");
      btnl6.setFont(Font.font("Calibri",FontWeight.BOLD,16));
      btnl6.setPrefSize(300,60);
      btnl6.setStyle(" -fx-base: #0066cc;");
  
      btnl6.setOnAction(new EventHandler&lt;ActionEvent&gt;() {
       @Override
       public void handle(ActionEvent e) {
        System.exit(0);
       }
       });
  
      vbox1.getChildren().addAll(btnl2,btnl4,btnl5,btnl6);
  
      return vbox1;
   }
   public static void main(String[] args) {
      launch(args);
   }
   }
  </code></pre>