com.sun.jdi.VMDisconnectedException: connection is closed
        at com.sun.tools.jdi.TargetVM.send(TargetVM.java:274)
        at com.sun.tools.jdi.VirtualMachineImpl.sendToTarget(VirtualMachineImpl.java:1011)
        at com.sun.tools.jdi.PacketStream.send(PacketStream.java:41)
        at com.sun.tools.jdi.JDWP$ThreadReference$Status.enqueueCommand(JDWP.java:5089)
        at com.sun.tools.jdi.JDWP$ThreadReference$Status.process(JDWP.java:5075)
        at com.sun.tools.jdi.ThreadReferenceImpl.jdwpStatus(ThreadReferenceImpl.java:185)
        at com.sun.tools.jdi.ThreadReferenceImpl.isSuspended(ThreadReferenceImpl.java:201)
        at org.netbeans.modules.debugger.jpda.models.JPDAThreadImpl.<init>(JPDAThreadImpl.java:104)
        at org.netbeans.modules.debugger.jpda.models.ObjectTranslation.createTranslation(ObjectTranslation.java:102)
        at org.netbeans.modules.debugger.jpda.models.ObjectTranslation.translate(ObjectTranslation.java:172)
        at org.netbeans.modules.debugger.jpda.JPDADebuggerImpl.getThread(JPDADebuggerImpl.java:1290)
        at org.netbeans.modules.debugger.jpda.models.JPDAThreadGroupImpl.getThreads(JPDAThreadGroupImpl.java:89)
        at org.netbeans.modules.debugger.jpda.models.ThreadsTreeModel.computeChildren(ThreadsTreeModel.java:155)
        at org.netbeans.modules.debugger.jpda.models.ThreadsTreeModel.recomputeChildren(ThreadsTreeModel.java:177)
        at org.netbeans.modules.debugger.jpda.models.ThreadsTreeModel.recomputeChildren(ThreadsTreeModel.java:181)
        at org.netbeans.modules.debugger.jpda.models.ThreadsTreeModel.recomputeChildren(ThreadsTreeModel.java:181)
        at org.netbeans.modules.debugger.jpda.models.ThreadsTreeModel.recomputeChildren(ThreadsTreeModel.java:181)
        at org.netbeans.modules.debugger.jpda.models.ThreadsTreeModel.recomputeChildren(ThreadsTreeModel.java:168)
        at org.netbeans.modules.debugger.jpda.models.ThreadsTreeModel.fireNodeChanged(ThreadsTreeModel.java:240)
        at org.netbeans.modules.debugger.jpda.models.ThreadsTreeModel$Listener$RefreshTree.run(ThreadsTreeModel.java:352)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:561)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:986)