1. Run SceneBuilderApp
2. Drag a "Pane" into the main window
3. Drag a Button (from the controls section) into the Pane
4. Drag a ComboBox into the Pane (put it below the Button)
5. In the right panel, expand the Layout Section for the ComboBox
6. Change "Min Width" to "USE_PREF_SIZE"
7. Click on the Button in the main window
8. Click on the ComboBox in the main window

You will get the following exception:

May 05, 2014 10:29:53 AM com.oracle.javafx.scenebuilder.app.SceneBuilderApp$SceneBuilderUncaughtExceptionHandler uncaughtException
SEVERE: An exception was thrown:
java.lang.NullPointerException
at com.sun.javafx.css.StyleManager.getCacheContainer(StyleManager.java:185)
at com.sun.javafx.css.StyleManager.getStyleMap(StyleManager.java:229)
at javafx.scene.CssStyleHelper$CacheContainer.getStyleMap(CssStyleHelper.java:395)
at javafx.scene.CssStyleHelper$CacheContainer.access$700(CssStyleHelper.java:333)
at javafx.scene.CssStyleHelper.getStyleMap(CssStyleHelper.java:454)
at javafx.scene.CssStyleHelper.lookupFont(CssStyleHelper.java:1686)
at javafx.scene.CssStyleHelper.transitionToState(CssStyleHelper.java:599)
at javafx.scene.Node.impl_processCSS(Node.java:8949)
at javafx.scene.Parent.impl_processCSS(Parent.java:1239)
at javafx.scene.Parent.impl_processCSS(Parent.java:1270)
at javafx.scene.Parent.impl_processCSS(Parent.java:1270)
at javafx.scene.Node.processCSS(Node.java:8822)
at javafx.scene.Node.applyCss(Node.java:8918)
at com.sun.javafx.scene.control.skin.ContextMenuContent.updateVisualItems(ContextMenuContent.java:265)
at com.sun.javafx.scene.control.skin.ContextMenuContent.updateItems(ContextMenuContent.java:159)
at com.sun.javafx.scene.control.skin.ContextMenuContent.lambda$setUpBinds$305(ContextMenuContent.java:744)
at com.sun.javafx.scene.control.skin.ContextMenuContent$$Lambda$431/11322697.onChanged(Unknown Source)
at com.sun.javafx.collections.ListListenerHelper$Generic.fireValueChangedEvent(ListListenerHelper.java:329)
at com.sun.javafx.collections.ListListenerHelper.fireValueChangedEvent(ListListenerHelper.java:73)
at javafx.collections.ObservableListBase.fireChange(ObservableListBase.java:233)
at javafx.collections.ListChangeBuilder.commit(ListChangeBuilder.java:482)
at javafx.collections.ListChangeBuilder.endChange(ListChangeBuilder.java:541)
at javafx.collections.ObservableListBase.endChange(ObservableListBase.java:205)
at javafx.collections.ModifiableObservableListBase.addAll(ModifiableObservableListBase.java:113)
at com.sun.javafx.scene.control.skin.MenuButtonSkinBase.lambda$new$380(MenuButtonSkinBase.java:115)
at com.sun.javafx.scene.control.skin.MenuButtonSkinBase$$Lambda$201/32048503.onChanged(Unknown Source)
at com.sun.javafx.collections.ListListenerHelper$Generic.fireValueChangedEvent(ListListenerHelper.java:329)
at com.sun.javafx.collections.ListListenerHelper.fireValueChangedEvent(ListListenerHelper.java:73)
at javafx.collections.ObservableListBase.fireChange(ObservableListBase.java:233)
at javafx.collections.ListChangeBuilder.commit(ListChangeBuilder.java:482)
at javafx.collections.ListChangeBuilder.endChange(ListChangeBuilder.java:541)
at javafx.collections.ObservableListBase.endChange(ObservableListBase.java:205)
at javafx.collections.ModifiableObservableListBase.add(ModifiableObservableListBase.java:155)
at java.util.AbstractList.add(AbstractList.java:108)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.editors.AutoSuggestEditor.addConstantsInMenuButton(AutoSuggestEditor.java:390)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.editors.AutoSuggestEditor.initConstants(AutoSuggestEditor.java:277)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.editors.AutoSuggestEditor.updateMenuButtonIfNeeded(AutoSuggestEditor.java:365)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.editors.AutoSuggestEditor.resetSuggestedList(AutoSuggestEditor.java:219)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.editors.AutoSuggestEditor.reset(AutoSuggestEditor.java:209)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.editors.DoubleEditor.reset(DoubleEditor.java:128)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.makeOrResetPropertyEditor(InspectorPanelController.java:1651)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.makePropertyEditor(InspectorPanelController.java:1617)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.getPropertyEditor(InspectorPanelController.java:1376)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.getInitializedPropertyEditor(InspectorPanelController.java:762)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.buildSection(InspectorPanelController.java:733)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.buildExpandedSection(InspectorPanelController.java:656)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.rebuild(InspectorPanelController.java:619)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.updateInspector(InspectorPanelController.java:573)
at com.oracle.javafx.scenebuilder.kit.editor.panel.inspector.InspectorPanelController.editorSelectionDidChange(InspectorPanelController.java:488)
at com.oracle.javafx.scenebuilder.kit.editor.panel.util.AbstractPanelController$6.changed(AbstractPanelController.java:250)
at com.oracle.javafx.scenebuilder.kit.editor.panel.util.AbstractPanelController$6.changed(AbstractPanelController.java:245)
at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.IntegerPropertyBase.fireValueChangedEvent(IntegerPropertyBase.java:106)
at javafx.beans.property.IntegerPropertyBase.markInvalid(IntegerPropertyBase.java:113)
at javafx.beans.property.IntegerPropertyBase.set(IntegerPropertyBase.java:146)
at com.oracle.javafx.scenebuilder.kit.editor.selection.Selection.incrementRevision(Selection.java:532)
at com.oracle.javafx.scenebuilder.kit.editor.selection.Selection.endUpdate(Selection.java:480)
at com.oracle.javafx.scenebuilder.kit.editor.selection.Selection.select(Selection.java:396)
at com.oracle.javafx.scenebuilder.kit.editor.selection.Selection.select(Selection.java:102)
at com.oracle.javafx.scenebuilder.kit.editor.selection.Selection.select(Selection.java:91)
at com.oracle.javafx.scenebuilder.kit.editor.panel.content.gesture.mouse.SelectAndMoveGesture.mousePressed(SelectAndMoveGesture.java:122)
at com.oracle.javafx.scenebuilder.kit.editor.panel.content.gesture.mouse.AbstractMouseDragGesture.start(AbstractMouseDragGesture.java:112)
at com.oracle.javafx.scenebuilder.kit.editor.panel.content.mode.EditModeController.activateGesture(EditModeController.java:955)
at com.oracle.javafx.scenebuilder.kit.editor.panel.content.mode.EditModeController.mousePressedOnGlassLayer(EditModeController.java:744)
at com.oracle.javafx.scenebuilder.kit.editor.panel.content.mode.EditModeController.access$300(EditModeController.java:96)
at com.oracle.javafx.scenebuilder.kit.editor.panel.content.mode.EditModeController$4.handle(EditModeController.java:555)
at com.oracle.javafx.scenebuilder.kit.editor.panel.content.mode.EditModeController$4.handle(EditModeController.java:552)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3719)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3447)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1723)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2456)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:348)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:273)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:382)
at com.sun.glass.ui.View.handleMouseEvent(View.java:553)
at com.sun.glass.ui.View.notifyMouse(View.java:925)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$126(WinApplication.java:102)
at com.sun.glass.ui.win.WinApplication$$Lambda$37/30463406.run(Unknown Source)
at java.lang.Thread.run(Thread.java:744)