java.lang.NullPointerException
        at org.netbeans.modules.debugger.jpda.projects.MainProjectManager.getProjectRoots(MainProjectManager.java:163)
        at org.netbeans.modules.debugger.jpda.projects.MainProjectManager.isDependent(MainProjectManager.java:142)
        at org.netbeans.modules.debugger.jpda.projects.MainProjectManager.getMainProject(MainProjectManager.java:105)
        at org.netbeans.modules.debugger.jpda.projects.StepIntoActionProvider.shouldBeEnabled(StepIntoActionProvider.java:130)
        at org.netbeans.modules.debugger.jpda.projects.StepIntoActionProvider.access$200(StepIntoActionProvider.java:70)
        at org.netbeans.modules.debugger.jpda.projects.StepIntoActionProvider$Listener.doSetEnabled(StepIntoActionProvider.java:181)
        at org.netbeans.modules.debugger.jpda.projects.StepIntoActionProvider$Listener.propertyChange(StepIntoActionProvider.java:158)
        at org.openide.util.WeakListenerImpl$PropertyChange.propertyChange(WeakListenerImpl.java:186)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:333)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:270)
        at org.netbeans.modules.debugger.jpda.projects.MainProjectManager.propertyChange(MainProjectManager.java:194)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:333)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:270)
        at org.netbeans.modules.project.ui.OpenProjectsTrampolineImpl.propertyChange(OpenProjectsTrampolineImpl.java:110)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:333)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:270)
        at org.netbeans.modules.project.ui.OpenProjectList.setMainProject(OpenProjectList.java:812)
        at org.netbeans.modules.project.ui.OpenProjectList$3.run(OpenProjectList.java:497)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)