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:934)
        at com.sun.tools.jdi.PacketStream.send(PacketStream.java:41)
        at com.sun.tools.jdi.JDWP$VirtualMachine$Version.enqueueCommand(JDWP.java:34)
        at com.sun.tools.jdi.JDWP$VirtualMachine$Version.process(JDWP.java:25)
        at com.sun.tools.jdi.VirtualMachineImpl.versionInfo(VirtualMachineImpl.java:531)
        at com.sun.tools.jdi.VirtualMachineImpl.hasNewCapabilities(VirtualMachineImpl.java:588)
        at com.sun.tools.jdi.VirtualMachineImpl.canRedefineClasses(VirtualMachineImpl.java:604)
        at org.netbeans.modules.debugger.jpda.JPDADebuggerImpl.canFixClasses(JPDADebuggerImpl.java:351)
        at org.netbeans.modules.debugger.jpda.projects.FixActionProvider.shouldBeEnabled(FixActionProvider.java:180)
        at org.netbeans.modules.debugger.jpda.projects.FixActionProvider.access$100(FixActionProvider.java:91)
        at org.netbeans.modules.debugger.jpda.projects.FixActionProvider$Listener.propertyChange(FixActionProvider.java:307)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:333)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:341)
        at org.netbeans.modules.debugger.jpda.JPDADebuggerImpl.firePropertyChange(JPDADebuggerImpl.java:1570)
        at org.netbeans.modules.debugger.jpda.JPDADebuggerImpl.setState(JPDADebuggerImpl.java:1554)
        at org.netbeans.modules.debugger.jpda.JPDADebuggerImpl.setRunning(JPDADebuggerImpl.java:1101)
        at org.netbeans.modules.debugger.jpda.actions.StartActionProvider.doStartDebugger(StartActionProvider.java:205)
        at org.netbeans.modules.debugger.jpda.actions.StartActionProvider.access$100(StartActionProvider.java:75)
        at org.netbeans.modules.debugger.jpda.actions.StartActionProvider$.run(StartActionProvider.java:165)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:573)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1005)