1. Open JavaTest Harness with a large suite (I used runtime 8a)
2. Create a work dir and a new configuration (after CE window opened I closed the window and replied No to save-changes warning)
3. Open Create report dialog, choose folder and start with default settings
4. Wait a bit (0-3 sec), close the report creation window using X button
5. Wait a bit (0-3 sec), close the JT main window

I reproduced this issue at least 5 times.

Exception:

java.lang.IllegalStateException: Shutdown in progress
at java.lang.ApplicationShutdownHooks.add(ApplicationShutdownHooks.java:66)
at java.lang.Runtime.addShutdownHook(Runtime.java:211)
at com.sun.javatest.TestResultCache.<init>(TestResultCache.java:158)
at com.sun.javatest.TestResultTable.awakeCache(TestResultTable.java:2133)
at com.sun.javatest.WorkDirectory.getTestResultTable(WorkDirectory.java:830)
at com.sun.javatest.LastRunFilter.accepts(LastRunFilter.java:151)
at com.sun.javatest.LastRunFilter.accepts(LastRunFilter.java:142)
at com.sun.javatest.TRT_Iterator.wouldAccept(TRT_Iterator.java:796)
at com.sun.javatest.TRT_Iterator.findNext(TRT_Iterator.java:637)
at com.sun.javatest.TRT_Iterator.init(TRT_Iterator.java:583)
at com.sun.javatest.TRT_Iterator.<init>(TRT_Iterator.java:90)
at com.sun.javatest.TestResultTable.getIterator(TestResultTable.java:833)
at com.sun.javatest.TestResultTable.getIterator(TestResultTable.java:737)
at com.sun.javatest.TestResultTable.getIterator(TestResultTable.java:901)
at com.sun.javatest.report.StatisticsSection.<init>(StatisticsSection.java:62)
at com.sun.javatest.report.HTMLReport.write(HTMLReport.java:100)
at com.sun.javatest.report.Report.writeReport(Report.java:596)
at com.sun.javatest.report.Report.doReport(Report.java:151)
at com.sun.javatest.report.Report.writeReports(Report.java:125)
at com.sun.javatest.exec.NewReportDialog.runReport(NewReportDialog.java:892)
at com.sun.javatest.exec.NewReportDialog.access$3600(NewReportDialog.java:100)
at com.sun.javatest.exec.NewReportDialog$6$1.run(NewReportDialog.java:1152)

If the wait time at steps 4, 5 is more than 4 seconds there is no exception, so it's a minor issue.