Program: 174846
Project: 174846
Buggy source:
public DisplayWindow(String name,String defaultWorld,SetupListener l) throws HeadlessException {
  super(name);
  this.moduleName=name;
  this.listener=l;
  this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
  JPanel setupPanel=new JPanel();
  setupPanel.setBackground(BACKGROUND);
  setupPanel.setLayout(new BoxLayout(setupPanel,BoxLayout.Y_AXIS));
  JLabel titleLabel=new JLabel("String_Node_Str" + name + "String_Node_Str");
  titleLabel.setAlignmentX(Component.CENTER_ALIGNMENT);
  titleLabel.setForeground(FOREGROUND);
  titleLabel.setMaximumSize(new Dimension(400,50));
  titleLabel.setPreferredSize(new Dimension(400,50));
  titleLabel.setFont(titleLabel.getFont().deriveFont(16f));
  setupPanel.add(titleLabel);
  JLabel setupDirLabel=new JLabel("String_Node_Str");
  setupDirLabel.setAlignmentX(Component.CENTER_ALIGNMENT);
  setupDirLabel.setForeground(FOREGROUND);
  setupDirLabel.setMaximumSize(new Dimension(400,40));
  setupDirLabel.setPreferredSize(new Dimension(400,20));
  setupPanel.add(setupDirLabel);
  JTextField directoryInput=new JTextField(MinecraftUtils.getDefaultMinecraftDir());
  directoryInput.setAlignmentX(Component.CENTER_ALIGNMENT);
  directoryInput.getDocument().putProperty("String_Node_Str",Boolean.TRUE);
  directoryInput.setBackground(BACKGROUND);
  directoryInput.setForeground(FOREGROUND);
  directoryInput.setCaretColor(FOREGROUND);
  directoryInput.setMaximumSize(new Dimension(400,25));
  directoryInput.setBorder(new CompoundBorder(new EmptyBorder(0,0,10,0),new CompoundBorder(new LineBorder(new Color(128,128,128)),new LineBorder(BACKGROUND,5))));
  setupPanel.add(directoryInput);
  JLabel setupSaveLabel=new JLabel("String_Node_Str");
  setupSaveLabel.setAlignmentX(Component.CENTER_ALIGNMENT);
  setupSaveLabel.setForeground(FOREGROUND);
  setupSaveLabel.setMaximumSize(new Dimension(400,40));
  setupSaveLabel.setPreferredSize(new Dimension(400,20));
  setupPanel.add(setupSaveLabel);
  JTextField worldInput=new JTextField(defaultWorld);
  worldInput.setAlignmentX(Component.CENTER_ALIGNMENT);
  worldInput.getDocument().putProperty("String_Node_Str",Boolean.TRUE);
  worldInput.setBackground(BACKGROUND);
  worldInput.setForeground(FOREGROUND);
  worldInput.setCaretColor(FOREGROUND);
  worldInput.setMaximumSize(new Dimension(400,25));
  worldInput.setBorder(new CompoundBorder(new EmptyBorder(0,0,10,0),new CompoundBorder(new LineBorder(new Color(128,128,128)),new LineBorder(BACKGROUND,5))));
  setupPanel.add(worldInput);
  JButton confirm=new JButton("String_Node_Str"){
    private final Color borderColor=new Color(150,150,150);
    private final Color rolloverColor=new Color(80,81,83);
    private final Color pressedColor=new Color(50,52,53);
    private final int borderThickness=1;
{
      this.setBorderPainted(false);
      this.setFocusPainted(false);
      this.setOpaque(false);
      this.setContentAreaFilled(false);
    }
    @Override protected void paintComponent(    Graphics g){
      g.setColor(borderColor);
      g.fillRect(0,0,this.getWidth(),this.getHeight());
      if (this.getModel().isPressed()) {
        g.setColor(pressedColor);
      }
 else       if (this.getModel().isRollover()) {
        g.setColor(rolloverColor);
      }
 else {
        g.setColor(this.getBackground());
      }
      g.fillRect(borderThickness,borderThickness,this.getWidth() - 2 * borderThickness,this.getHeight() - 2 * borderThickness);
      super.paintComponent(g);
    }
  }
;
  confirm.setBackground(new Color(70,72,75));
  confirm.setForeground(FOREGROUND);
  confirm.addActionListener(e -> {
    this.directory=directoryInput.getText();
    this.world=worldInput.getText();
    this.dispatchSetupEvent();
    this.updateContentPane();
  }
);
  setupPanel.add(confirm);
  JPanel endPadding=new JPanel();
  endPadding.setOpaque(false);
  setupPanel.add(endPadding);
  setupPanel.setPreferredSize(new Dimension(500,200));
  this.setContentPane(setupPanel);
  this.pack();
  this.setVisible(true);
}

Fixed version (ground truth):
public DisplayWindow(String name,String defaultWorld,SetupListener l) throws HeadlessException {
  super(name);
  this.moduleName=name;
  this.listener=l;
  this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
  JPanel setupPanel=new JPanel();
  setupPanel.setBackground(BACKGROUND);
  setupPanel.setLayout(new BoxLayout(setupPanel,BoxLayout.Y_AXIS));
  JLabel titleLabel=new JLabel("String_Node_Str" + name + "String_Node_Str");
  titleLabel.setAlignmentX(Component.CENTER_ALIGNMENT);
  titleLabel.setForeground(FOREGROUND);
  titleLabel.setMaximumSize(new Dimension(400,50));
  titleLabel.setPreferredSize(new Dimension(400,50));
  titleLabel.setFont(titleLabel.getFont().deriveFont(16f));
  setupPanel.add(titleLabel);
  JLabel setupDirLabel=new JLabel("String_Node_Str");
  setupDirLabel.setAlignmentX(Component.CENTER_ALIGNMENT);
  setupDirLabel.setForeground(FOREGROUND);
  setupDirLabel.setMaximumSize(new Dimension(400,40));
  setupDirLabel.setPreferredSize(new Dimension(400,20));
  setupPanel.add(setupDirLabel);
  JTextField directoryInput=new JTextField(MinecraftUtils.getDefaultMinecraftDir());
  directoryInput.setAlignmentX(Component.CENTER_ALIGNMENT);
  directoryInput.getDocument().putProperty("String_Node_Str",Boolean.TRUE);
  directoryInput.setBackground(BACKGROUND);
  directoryInput.setForeground(FOREGROUND);
  directoryInput.setCaretColor(FOREGROUND);
  directoryInput.setMaximumSize(new Dimension(400,25));
  directoryInput.setBorder(new CompoundBorder(new EmptyBorder(0,0,10,0),new CompoundBorder(new LineBorder(new Color(128,128,128)),new LineBorder(BACKGROUND,5))));
  setupPanel.add(directoryInput);
  JLabel setupSaveLabel=new JLabel("String_Node_Str");
  setupSaveLabel.setAlignmentX(Component.CENTER_ALIGNMENT);
  setupSaveLabel.setForeground(FOREGROUND);
  setupSaveLabel.setMaximumSize(new Dimension(400,40));
  setupSaveLabel.setPreferredSize(new Dimension(400,20));
  setupPanel.add(setupSaveLabel);
  JTextField worldInput=new JTextField(defaultWorld);
  worldInput.setAlignmentX(Component.CENTER_ALIGNMENT);
  worldInput.getDocument().putProperty("String_Node_Str",Boolean.TRUE);
  worldInput.setBackground(BACKGROUND);
  worldInput.setForeground(FOREGROUND);
  worldInput.setCaretColor(FOREGROUND);
  worldInput.setMaximumSize(new Dimension(400,25));
  worldInput.setBorder(new CompoundBorder(new EmptyBorder(0,0,10,0),new CompoundBorder(new LineBorder(new Color(128,128,128)),new LineBorder(BACKGROUND,5))));
  setupPanel.add(worldInput);
  JButton confirm=new JButton("String_Node_Str"){
    private final Color borderColor=new Color(150,150,150);
    private final Color rolloverColor=new Color(80,81,83);
    private final Color pressedColor=new Color(50,52,53);
    private final int borderThickness=1;
{
      this.setBorderPainted(false);
      this.setFocusPainted(false);
      this.setOpaque(false);
      this.setContentAreaFilled(false);
    }
    @Override protected void paintComponent(    Graphics g){
      g.setColor(borderColor);
      g.fillRect(0,0,this.getWidth(),this.getHeight());
      if (this.getModel().isPressed()) {
        g.setColor(pressedColor);
      }
 else       if (this.getModel().isRollover()) {
        g.setColor(rolloverColor);
      }
 else {
        g.setColor(this.getBackground());
      }
      g.fillRect(borderThickness,borderThickness,this.getWidth() - 2 * borderThickness,this.getHeight() - 2 * borderThickness);
      super.paintComponent(g);
    }
  }
;
  confirm.setBackground(new Color(70,72,75));
  confirm.setForeground(FOREGROUND);
  Runnable confirmAction=() -> {
    this.directory=directoryInput.getText();
    this.world=worldInput.getText();
    this.dispatchSetupEvent();
    this.updateContentPane();
  }
;
  directoryInput.addKeyListener(new KeyAdapter(){
    @Override public void keyPressed(    KeyEvent e){
      if (e.getKeyCode() == KeyEvent.VK_ENTER) {
        confirmAction.run();
      }
    }
  }
);
  worldInput.addKeyListener(new KeyAdapter(){
    @Override public void keyPressed(    KeyEvent e){
      if (e.getKeyCode() == KeyEvent.VK_ENTER) {
        confirmAction.run();
      }
    }
  }
);
  confirm.addActionListener(e -> confirmAction.run());
  setupPanel.add(confirm);
  JPanel endPadding=new JPanel();
  endPadding.setOpaque(false);
  setupPanel.add(endPadding);
  setupPanel.setPreferredSize(new Dimension(500,200));
  this.setContentPane(setupPanel);
  this.pack();
  this.setVisible(true);
}