com.sun.jdi.IncompatibleThreadStateException
        at com.sun.tools.jdi.ThreadReferenceImpl.privateFrames(ThreadReferenceImpl.java:365)
        at com.sun.tools.jdi.ThreadReferenceImpl.frame(ThreadReferenceImpl.java:277)
        at org.netbeans.modules.debugger.jpda.jdi.ThreadReferenceWrapper.frame(ThreadReferenceWrapper.java:118)
        at org.netbeans.modules.debugger.jpda.actions.StepActionProvider.exec(StepActionProvider.java:334)
        at org.netbeans.modules.debugger.jpda.util.Operator$1.run(Operator.java:327)
        at java.lang.Thread.run(Thread.java:619)