Элементы не отображаются в палитре в Eclipse Oxygen.

Я использую Eclipse для разработчиков RCP и RAP (Oxygen). При открытии палитры она пуста. Хотя у меня есть код в режиме редактирования на вкладке исходного кода. На изображении ниже палитра пуста

Как предложено, добавлен код ниже.

При открытии вкладки «Дизайн» палитра пуста.

package com.jcg.rca.main;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CLabel;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;

import org.eclipse.swt.widgets.MessageBox;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
//import org.eclipse.wb.swt.SWTResourceManager;

public class MainWindow {

protected Shell shlLogin;
private Text userNameTxt;
private Text passwordTxt;

private String userName = null;
private String password = null;

/**
 * Launch the application.
 * 
 * @param args
 */
public static void main(String[] args) {
    try {
        MainWindow window = new MainWindow();
        window.open();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

/**
 * Open the window.
 */
public void open() {
    Display display = Display.getDefault();
    createContents();
    shlLogin.open();
    shlLogin.layout();
    while (!shlLogin.isDisposed()) {
        if (!display.readAndDispatch()) {

            display.sleep();

        }
    }
}

/**
 * Create contents of the window.
 */
protected void createContents() {
    shlLogin = new Shell(SWT.CLOSE | SWT.TITLE | SWT.MIN);
    shlLogin.setSize(450, 300);
    shlLogin.setText("Login");

    CLabel label = new CLabel(shlLogin, SWT.NONE);
    //label.setImage(SWTResourceManager.getImage(MainWindow.class, "/com/jcg/rca/main/eclipse_logo.png"));
    label.setBounds(176, 10, 106, 70);
    label.setText("");

    Label lblUsername = new Label(shlLogin, SWT.NONE);
    lblUsername.setBounds(125, 115, 55, 15);
    lblUsername.setText("Username");

    Label lblPassword = new Label(shlLogin, SWT.NONE);
    lblPassword.setBounds(125, 144, 55, 15);
    lblPassword.setText("Password");

    userNameTxt = new Text(shlLogin, SWT.BORDER);
    userNameTxt.setBounds(206, 109, 173, 21);

    passwordTxt = new Text(shlLogin, SWT.BORDER | SWT.PASSWORD);
    passwordTxt.setBounds(206, 144, 173, 21);

    Button btnLogin = new Button(shlLogin, SWT.NONE);
    btnLogin.setBounds(206, 185, 75, 25);
    btnLogin.setText("Login");

    btnLogin.addListener(SWT.Selection, new Listener() {
        public void handleEvent(Event event) {

            userName = userNameTxt.getText();
            password = passwordTxt.getText();

            if (userName == null || userName.isEmpty() || password == null || password.isEmpty()) {
                String errorMsg = null;
                MessageBox messageBox = new MessageBox(shlLogin, SWT.OK | SWT.ICON_ERROR);

                messageBox.setText("Alert");
                if (userName == null || userName.isEmpty()) {
                    errorMsg = "Please enter username";
                } else if (password == null || password.isEmpty()) {
                    errorMsg = "Please enter password";
                }
                if (errorMsg != null) {
                    messageBox.setMessage(errorMsg);
                    messageBox.open();
                }
            } else {
                MessageBox messageBox = new MessageBox(shlLogin, SWT.OK | SWT.ICON_WORKING);
                messageBox.setText("Info");
                messageBox.setMessage("Valid");
                messageBox.open();
            }
        }
    });

}}

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