To reproduce the problem please run the following testcase(RobotDemo.java)
You will get the following message..
Couldn't execl robot child process: No such file or directory

    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    
    public class RobotDemo {
        protected void run() throws AWTException {
    
            // set up frames and panels
    
            JFrame frame = new JFrame("RobotDemo");
            JPanel panel = new JPanel();
            panel.setLayout(new GridLayout(3, 1));
    
            // set up fields, labels, and buttons
    
            final JTextField field = new JTextField(10);
            field.setFont(new Font("Lusida Sans", Font.PLAIN, 24));
            final JLabel lab = new JLabel();
            field.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    String s = "Length: " +
                        field.getText().length();
                    lab.setText(s);
                }
            });
            JButton button = new JButton("Exit");
            button.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    System.exit(0);
                }
            });
    
            // add components to panel and display
    
            panel.add(field);
            panel.add(lab);
            panel.add(button);
            frame.getContentPane().add(panel);
            frame.setSize(200, 150);
            frame.setLocation(200, 200);
            frame.setVisible(true);
    
            // create a robot to feed in GUI events
    
            Robot rob = new Robot();
    
            // enter some keystrokes
    
            int keyinput[] = {
                KeyEvent.VK_T,
                KeyEvent.VK_E,
                KeyEvent.VK_S,
                KeyEvent.VK_T,
                KeyEvent.VK_I,
                KeyEvent.VK_N,
                KeyEvent.VK_G
            };
            rob.delay(1000);
            rob.keyPress(KeyEvent.VK_SHIFT);
            field.requestFocus();
            for (int i = 0; i < keyinput.length; i++) {
                rob.keyPress(keyinput[i]);
                rob.delay(1000);
            }
            rob.keyRelease(KeyEvent.VK_SHIFT);
            rob.keyPress(KeyEvent.VK_ENTER);
    
            // move cursor to Exit button
    
            Point p = button.getLocationOnScreen();
            rob.mouseMove(p.x + 5, p.y + 5);
            rob.delay(2000);
    
            // press and release left mouse button
    
            rob.mousePress(InputEvent.BUTTON1_MASK);
            rob.delay(2000);
            rob.mouseRelease(InputEvent.BUTTON1_MASK);
        }

public static void main(String[] args){

try{
RobotDemo robotdemo = new RobotDemo();
robotdemo.run();
}catch(AWTException awtexecp){
awtexecp.printStackTrace();
}
}

    }