cannot edit wrong JBossWS runtime

create new JBossWS runtime in Preferences>Web Services->JBossWS Preferences and use $JBOSS_AS_6 as 'Home folder' and '2.0' as version
select newly created runtime in Preferences>Web Services->JBossWS Preferences tab
-click on 'Edit' button

=> nothing happens and in the error log, there is:
java.lang.NullPointerException
at org.jboss.tools.ws.ui.preferences.JBossWSRuntimeListFieldEditor$JBossWSRuntimeWizardPage.propertyChange(JBossWSRuntimeListFieldEditor.java:528)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
at org.jboss.tools.common.ui.widget.editor.BaseFieldEditor.setValue(BaseFieldEditor.java:224)
at org.jboss.tools.common.ui.widget.editor.CompositeEditor.setValue(CompositeEditor.java:126)
at org.jboss.tools.ws.ui.preferences.JBossWSRuntimeListFieldEditor$JBossWSRuntimeWizardPage.createControl(JBossWSRuntimeListFieldEditor.java:469)
at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:170)
at org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:734)
at org.eclipse.jface.wizard.WizardDialog.createContents(WizardDialog.java:606)
at org.eclipse.jface.window.Window.create(Window.java:431)
at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1089)
at org.eclipse.jface.window.Window.open(Window.java:790)
at org.jboss.tools.ws.ui.preferences.JBossWSRuntimeListFieldEditor$EditAction.run(JBossWSRuntimeListFieldEditor.java:1019)
at org.jboss.tools.ws.ui.preferences.JBossWSRuntimeListFieldEditor$ActionButton$1.widgetSelected(JBossWSRuntimeListFieldEditor.java:864)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:234)
....