com.sun.jdi.VMDisconnectedException: Connection 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$ThreadGroupReference$Name.enqueueCommand(JDWP.java:5790)
        at com.sun.tools.jdi.JDWP$ThreadGroupReference$Name.process(JDWP.java:5776)
        at com.sun.tools.jdi.ThreadGroupReferenceImpl.name(ThreadGroupReferenceImpl.java:45)
        at org.netbeans.modules.debugger.jpda.models.JPDAThreadGroupImpl.getName(JPDAThreadGroupImpl.java:109)
        at org.netbeans.modules.debugger.jpda.ui.models.DebuggingNodeModel.getDisplayName(DebuggingNodeModel.java:187)
        at org.netbeans.spi.viewmodel.Models$DelegatingNodeModel.getDisplayName(Models.java:1875)
        at org.netbeans.modules.debugger.jpda.ui.models.DebuggingMonitorModel.getDisplayName(DebuggingMonitorModel.java:380)
        at org.netbeans.spi.viewmodel.Models$CompoundNodeModel.getDisplayName(Models.java:813)
        at org.netbeans.spi.viewmodel.Models$CompoundModel.getDisplayName(Models.java:3023)
        at org.netbeans.modules.viewmodel.TreeModelNode.refreshNode(TreeModelNode.java:412)
        at org.netbeans.modules.viewmodel.TreeModelNode.access$300(TreeModelNode.java:85)
        at org.netbeans.modules.viewmodel.TreeModelNode$2.run(TreeModelNode.java:305)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)