To reproduce:
- drop attached jfxtras jar file to the lib
- put on content the Agenda found in Custom section of the lib
- on Content the rendering of the Agenda is weird, as if detected width x height is 0 x 0; try to make it bigger by initiating a resize from the blue cross (see attached capture)

Exception in thread "JavaFX Application Thread" java.lang.AssertionError
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.util.LineEquation.<init>(LineEquation.java:22)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.util.LineEquation.<init>(LineEquation.java:33)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.HudWindowController.computePopupLocation(HudWindowController.java:174)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.HudWindowController.updatePopupLocation(HudWindowController.java:131)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.HudWindowController.anchorBoundsDidChange(HudWindowController.java:111)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.util.AbstractPopupController.openWindow(AbstractPopupController.java:73)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.gesture.mouse.ResizeGesture.setupAndOpenHudWindow(ResizeGesture.java:434)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.gesture.mouse.ResizeGesture.mouseDragStarted(ResizeGesture.java:92)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.gesture.mouse.AbstractMouseGesture$1.handle(AbstractMouseGesture.java:81)
    at com.oracle.javafx.scenebuilder.kit.editor.panel.content.gesture.mouse.AbstractMouseGesture$1.handle(AbstractMouseGesture.java:76)
    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:203)
    at javafx.scene.Scene$DnDGesture.fireEvent(Scene.java:2825)
    at javafx.scene.Scene$DnDGesture.process(Scene.java:2903)
    at javafx.scene.Scene$DnDGesture.access$8500(Scene.java:2801)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3637)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3391)
    at javafx.scene.Scene$MouseHandler.access$1800(Scene.java:3342)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1626)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2401)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:323)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:248)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:365)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:525)