Start SB
Invoke View -> Show Sample Controller Skeleton
You will get :

java.lang.NullPointerException
at com.oracle.javafx.scenebuilder.app.skeleton.SkeletonBuffer.constructPackageLine(SkeletonBuffer.java:100)
at com.oracle.javafx.scenebuilder.app.skeleton.SkeletonBuffer.construct(SkeletonBuffer.java:156)
at com.oracle.javafx.scenebuilder.app.skeleton.SkeletonBuffer.toString(SkeletonBuffer.java:228)
at com.oracle.javafx.scenebuilder.app.skeleton.SkeletonWindowController.update(SkeletonWindowController.java:186)
at com.oracle.javafx.scenebuilder.app.skeleton.SkeletonWindowController.openWindow(SkeletonWindowController.java:118)
at com.oracle.javafx.scenebuilder.app.DocumentWindowController.performControlAction(DocumentWindowController.java:764)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$DocumentControlActionController.perform(MenuBarController.java:1549)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.handleOnActionMenu(MenuBarController.java:1080)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.access$800(MenuBarController.java:88)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$20.handle(MenuBarController.java:1073)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$20.handle(MenuBarController.java:1069)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:204)
at javafx.scene.control.MenuItem.fire(MenuItem.java:462)
at com.sun.javafx.scene.control.GlobalMenuAdapter$5.handle(GlobalMenuAdapter.java:158)
at com.sun.javafx.scene.control.GlobalMenuAdapter$5.handle(GlobalMenuAdapter.java:156)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:204)
at javafx.scene.control.MenuItem.fire(MenuItem.java:462)
at com.sun.javafx.tk.quantum.GlassSystemMenu$6.action(GlassSystemMenu.java:234)