...demo I get an assert failure:

C:\dwt-samples\jface>librarian tango.core.Exception.AssertException...

...import dwt.widgets.ToolBar;
import dwt.widgets.ToolItem;
import dwt.widgets.MessageBox;
import dwt.DWT...

...2
 */

import dwt.DWT;
import dwt.custom.StyledText;
import dwt.custom.StyleRange;
import dwt.layout...

...import dwt.widgets.ToolBar;
import dwt.widgets.ToolItem;
import dwt.widgets.MessageBox;
import dwt.DWT...

...import dwt.widgets.ToolBar;
import dwt.widgets.ToolItem;
import dwt.widgets.MessageBox;
import dwt.DWT...

It is added.

...should be seen as an error in DWT.

The real problem was in ArrayWrapperT that...

...import dwt.graphics.Image;
import dwt.graphics.ImageData;

import dwt.widgets.Display;
import dwt.dwthelper...

...import dwt.graphics.Image;
import dwt.widgets.Dialog;
import dwt.widgets.MessageBox;
import dwt.DWT...

...images) {
    checkWidget ();
    // DWT extension: allow null array
    //if (images is null) error (DWT.ERROR_INVALID...