'NullPointerException' when trying to close a window

hi,

i can't close close one of my test case tabs. I keep getting the following error below. problem occurs even if i restart soapui, it's always the same testcase window that won't close.

The only major change was that I just switched from 2.5.2 build 3_08 to build 4_01. (no changes were made to the testcase).

Thanks for your help.


-----STACK-----
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
        at com.eviware.soapui.support.editor.views.xml.form2.xml.AbstractXmlFormEditorParticle.befor
eSave(SourceFile:115)
        at com.eviware.soapui.support.editor.views.xml.form2.xml.RootXmlFormEditorParticle.beforeSav
e(SourceFile:86)
        at com.eviware.soapui.support.editor.views.xml.form2.wsdl.AbstractWsdlFormEditorModel.getXml
(SourceFile:261)
        at com.eviware.soapui.support.editor.views.xml.form2.FormEditorView.saveDocument(SourceFile:
213)
        at com.eviware.soapui.support.editor.xml.XmlEditor.saveDocument(XmlEditor.java:35)
        at com.eviware.soapui.impl.support.panels.AbstractHttpRequestDesktopPanel.onClose(AbstractHt
tpRequestDesktopPanel.java:633)
        at com.eviware.soapui.impl.wsdl.panels.teststeps.WsdlTestRequestDesktopPanel.onClose(WsdlTes
tRequestDesktopPanel.java:236)
        at com.eviware.soapui.ui.TabbedSoapUIDesktop.a(SourceFile:169)
        at com.eviware.soapui.ui.TabbedSoapUIDesktop.a(SourceFile:51)
        at com.eviware.soapui.ui.TabbedSoapUIDesktop$InternalDockingWindowListener.windowClosing(Sou
rceFile:311)
        at net.infonode.docking.DockingWindow.fireWindowClosing(Unknown Source)
        at net.infonode.docking.DockingWindow.fireWindowClosing(Unknown Source)
        at net.infonode.docking.DockingWindow.fireWindowClosing(Unknown Source)
        at net.infonode.docking.DockingWindow.closeWithAbort(Unknown Source)
        at net.infonode.docking.action.CloseWithAbortWindowAction.perform(Unknown Source)
        at net.infonode.docking.action.DockingWindowAction$1.perform(Unknown Source)
        at net.infonode.gui.action.SimpleAction$1.actionPerformed(Unknown Source)
        at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
        at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
        at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
        at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
        at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
        at java.awt.Component.processMouseEvent(Unknown Source)
        at javax.swing.JComponent.processMouseEvent(Unknown Source)
        at java.awt.Component.processEvent(Unknown Source)
        at java.awt.Container.processEvent(Unknown Source)
        at java.awt.Component.dispatchEventImpl(Unknown Source)
        at java.awt.Container.dispatchEventImpl(Unknown Source)
        at java.awt.Component.dispatchEvent(Unknown Source)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
        at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
        at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
        at java.awt.Container.dispatchEventImpl(Unknown Source)
        at java.awt.Window.dispatchEventImpl(Unknown Source)
        at java.awt.Component.dispatchEvent(Unknown Source)
        at java.awt.EventQueue.dispatchEvent(Unknown Source)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.run(Unknown Source)