[news.eclipse.platform.rcp] org.eclipse.jface.util.Assert$AssertionFail

[brigitte.ilsanker@xxxxxxxxx (Brigitte Ilsanker)]

Have developed a standalone wizard which is opened when pressing a button 
of a subclass of ApplicationWindow. The button listener does: 
..
MyWizard wizard = new MyWizard();
WizardDialog dialog = new WizardDialog(getShell(), wizard);
dialog.setBlockOnOpen(true);

Everything works fine with three Wizard Pages. Now I introduced a forth 
page that looks the same as the other pages (a constructor and a 
createControl method).

public void addPages() {
  addPage(new FirstPage());
  addPage(new SecondPage());
  addPage(new ThirdPage());
  addPage(new ForthPage());
}

> From now on it doesn't work any more. Upon clicking the button, the 
console says:

org.eclipse.jface.util.Assert$AssertionFailedException: null argument;
	at org.eclipse.jface.util.Assert.isNotNull(Assert.java:149)
	at org.eclipse.jface.util.Assert.isNotNull(Assert.java:125)
	at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:183)
	at 
org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:611)
	at 
org.eclipse.jface.wizard.WizardDialog.createContents(WizardDialog.java:502)
	at org.eclipse.jface.window.Window.create(Window.java:418)
	at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:996)
 ... 
 
Googling brings links to some bugs that seem to be resolved. 

The eclipse help says:
Assertion failure exceptions, like most runtime exceptions, are thrown 
when something is misbehaving. ... If you find yourself in the position 
where you need to catch an assertion failure, you have most certainly 
written your program incorrectly. 

Hmm, that doesn't help very much.

Any hint is appreciated.
Brigitte