1) java -jar javatest.jar -newDesktop
2) close quick start guide
3) file->open->test suite: jck-8a-b09 sampleJCK-compiler-8a
4) create workdir
5) report->create report (html, plain), default settings, Yes in open after creation
6) leaving the report open, launch Tools->Report Converter
7) press help in Create a report dialog
(now we have four windows: JT, Report browser, Online help, 'Create a report' dialog)
8) press Report directory->Browse (fifth window)
9) with active OpenFile Dialog press close window button in windows Online help, Report browser
... nothing visible happens at this point ...
(but I think at this time exception occurs)
10) close OpenFile Dialog, close all other windows
11) the exception message is output to stderr

(please see screenshot attached)

I think this happens because Report Generation thread is not properly shut down

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
        at com.sun.jck.interview.JCKParameters.getRelevantTestFilter(JCKParameters.java:142)
        at com.sun.javatest.InterviewParameters.getFilters(InterviewParameters.java:762)
        at com.sun.javatest.mrep.OptionsPane.getCustomReports(OptionsPane.java:257)
        at com.sun.javatest.mrep.OptionsPane.initGUI(OptionsPane.java:162)
        at com.sun.javatest.mrep.OptionsPane.<init>(OptionsPane.java:91)
        at com.sun.javatest.mrep.OptionsDialog.initGUI(OptionsDialog.java:122)
        at com.sun.javatest.tool.ToolDialog.initMain(ToolDialog.java:714)
        at com.sun.javatest.tool.ToolDialog.setContentPane(ToolDialog.java:302)
        at com.sun.javatest.tool.ToolDialog.setBody(ToolDialog.java:383)
        at com.sun.javatest.mrep.OptionsDialog.cleanUp(OptionsDialog.java:184)
        at com.sun.javatest.mrep.OptionsDialog.windowClosingAction(OptionsDialog.java:114)
        at com.sun.javatest.tool.ToolDialog$2.windowClosing(ToolDialog.java:565)
        at java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:349)
        at java.awt.Window.processWindowEvent(Window.java:2058)
        at javax.swing.JDialog.processWindowEvent(JDialog.java:682)
        at java.awt.Window.processEvent(Window.java:2017)
        at java.awt.Component.dispatchEventImpl(Component.java:4883)
        at java.awt.Container.dispatchEventImpl(Container.java:2292)
        at java.awt.Window.dispatchEventImpl(Window.java:2739)
        at java.awt.Component.dispatchEvent(Component.java:4705)
        at com.sun.javatest.tool.ToolDialog.closing(ToolDialog.java:691)
        at com.sun.javatest.tool.ToolDialog.access$000(ToolDialog.java:69)
        at com.sun.javatest.tool.ToolDialog$1.toolDisposed(ToolDialog.java:137)
        at com.sun.javatest.tool.Tool.dispose(Tool.java:241)
        at com.sun.javatest.tool.DeskView.dispose(DeskView.java:123)
        at com.sun.javatest.tool.TabDeskView.dispose(TabDeskView.java:111)
        at com.sun.javatest.tool.Desktop.dispose(Desktop.java:1180)
        at com.sun.javatest.tool.Desktop.checkToolsAndExitIfOK(Desktop.java:618)
        at com.sun.javatest.tool.TabDeskView$2.windowClosing(TabDeskView.java:379)
        at java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:350)
        at java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:349)
        at java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:349)
        at java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:349)
        at java.awt.Window.processWindowEvent(Window.java:2058)
        at javax.swing.JFrame.processWindowEvent(JFrame.java:297)
        at java.awt.Window.processEvent(Window.java:2017)
        at java.awt.Component.dispatchEventImpl(Component.java:4883)
        at java.awt.Container.dispatchEventImpl(Container.java:2292)
        at java.awt.Window.dispatchEventImpl(Window.java:2739)
        at java.awt.Component.dispatchEvent(Component.java:4705)
        at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)
        at java.awt.EventQueue.access$400(EventQueue.java:97)
        at java.awt.EventQueue$3.run(EventQueue.java:697)
        at java.awt.EventQueue$3.run(EventQueue.java:691)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
        at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
        at java.awt.EventQueue$4.run(EventQueue.java:719)
        at java.awt.EventQueue$4.run(EventQueue.java:717)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)