WindowBuilder遇到意外的内部错误;不能演员？

Question

我正在尝试运行WindowBuilder来构建一些SWT应用程序。但是，当我单击“设计”选项卡时，出现此错误：

我正在使用的代码产生上述错误只是启动新项目时的基本默认代码。当我尝试运行在Java中执行时运行的实际SWT项目时，会发生同样的错误：

以下是代码：

package ch2;
import org.eclipse.swt.*;

public class HelloSWT {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Hello World");
        shell.setBounds(100, 100, 200, 50);

        //Layout
        RowLayout rowLay = new RowLayout(SWT.HORIZONTAL);
        rowLay.justify = true;
        rowLay.marginTop = 20;
        rowLay.marginBottom = 20;
        //Form Layout
        FormData formData = new FormData();
        formData.right = new FormAttachment(100, -5);
        formData.bottom = new FormAttachment(100, -5);


        //shell.setLayout(new FillLayout(SWT.VERTICAL));
        shell.setLayout(rowLay);

        final Label label = new Label(shell, SWT.CENTER);
        label.setText("Hello Inside World");
            org.eclipse.swt.graphics.Color red = new org.eclipse.swt.graphics.Color(display, 255, 0, 0);
        label.setForeground(red);

        //Button 
        final Button button = new Button(shell, 0);
        button.setText("A Button");
            Image img = new Image(display, "C:\\Users\\ra_stein\\Pictures\\koala.png");
        button.setImage(img);
        button.setForeground(red);
        button.pack();
        button.addSelectionListener(new SelectionAdapter(){
            public void widgetSelected(SelectionEvent event){
                button.setText("A clicked Button");
                label.setText("Hello Yourself");
            }
        });

        Text txt = new Text(shell, SWT.SINGLE);
        txt.setText("Text Object");
        txt.addVerifyListener(new VerifyListener(){
                public void verifyText(VerifyEvent event){
                    event.doit = event.text.length() == 1 || Character.isDigit(event.text.charAt(0)); //set doit to true if the length of the event.text (the text I want to put in) is exactly one OR the the first character is a digit.
                }
            }
        );

        //Table
        final Table table = new Table(shell, SWT.SINGLE | SWT.BORDER | SWT.FULL_SELECTION);
        table.setHeaderVisible(true);
        table.setLinesVisible(true);
        TableColumn column1 = new TableColumn(table, SWT.NULL);
        column1.setText("Name");
        column1.pack();
        TableColumn column2 = new TableColumn(table, SWT.NULL);
        column2.setText("Age");
        column2.pack();
        TableItem item1 = new TableItem(table, SWT.NULL);
        item1.setText(new String[] {"Dan", "43"});
        TableItem item2 = new TableItem(table, SWT.NULL);
        item2.setText(new String[] {"John", "23"});
        table.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent event){
                TableItem[] selected = table.getSelection();
                if (selected.length > 0){
                    System.out.println("Name: " + selected[0].getText(0));
                    System.out.println("Age: " + selected[0].getText(1));
                }
            }

        });

        //Tab Folder
        final TabFolder tabFolder = new TabFolder(shell, SWT.BORDER);
        TabItem tabItem1 = new TabItem(tabFolder, SWT.NULL);
        tabItem1.setText("Tab 1");
        TabItem tabItem2 = new TabItem(tabFolder, SWT.NULL);
        tabItem2.setText("Tab 2");

        Composite compo = new Composite(tabFolder, SWT.NULL);
        tabItem2.setControl(compo);





        //Text helloText = new Text(shell, SWT.CENTER);
        //helloText.setText("Hello SWT");
        //helloText.pack();

        shell.pack();
        shell.open();

        while(!shell.isDisposed()){
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();


    }

}

这是错误：