I'm investigating an issue with my application where things are working fine running with JavaFX 2.2 on 7u55, but I have a particular case where 8u5 is throwing the following exception during layout:
Exception in thread "JavaFX Application Thread" java.lang.NullPointerException at javafx.scene.layout.GridPane.computeMinHeights(GridPane.java:1450) at javafx.scene.layout.GridPane.computeMinHeight(GridPane.java:1224) at javafx.scene.Parent.minHeight(Parent.java:946) at javafx.scene.layout.Region.minHeight(Region.java:1404) at javafx.scene.layout.Region.computeChildMinAreaHeight(Region.java:1700) at javafx.scene.layout.Region.getMaxAreaHeight(Region.java:1981) at javafx.scene.layout.Region.computeMaxMinAreaHeight(Region.java:1854) at javafx.scene.layout.StackPane.computeMinHeight(StackPane.java:293) at javafx.scene.Parent.minHeight(Parent.java:946) at javafx.scene.layout.Region.minHeight(Region.java:1404) at javafx.scene.layout.Region.computeChildPrefAreaHeight(Region.java:1765) at javafx.scene.layout.Region.getMaxAreaHeight(Region.java:1982) at javafx.scene.layout.Region.computeMaxPrefAreaHeight(Region.java:1884) at javafx.scene.layout.StackPane.computePrefHeight(StackPane.java:310) at javafx.scene.Parent.prefHeight(Parent.java:918) at javafx.scene.layout.Region.prefHeight(Region.java:1438) at com.sun.javafx.scene.control.skin.TitledPaneSkin.computePrefHeight(TitledPaneSkin.java:249) at javafx.scene.control.Control.computePrefHeight(Control.java:543) at javafx.scene.Parent.prefHeight(Parent.java:918) at javafx.scene.layout.Region.prefHeight(Region.java:1438) at javafx.scene.layout.Region.computeChildPrefAreaHeight(Region.java:1765) at javafx.scene.layout.GridPane.computePrefHeights(GridPane.java:1407) at javafx.scene.layout.GridPane.computePrefHeight(GridPane.java:1242) at javafx.scene.Parent.prefHeight(Parent.java:918) at javafx.scene.layout.Region.prefHeight(Region.java:1438) at com.sun.javafx.scene.control.skin.ScrollPaneSkin.computeScrollNodeSize(ScrollPaneSkin.java:916) at com.sun.javafx.scene.control.skin.ScrollPaneSkin.layoutChildren(ScrollPaneSkin.java:791) at javafx.scene.control.Control.layoutChildren(Control.java:574) at javafx.scene.Parent.layout(Parent.java:1076) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Parent.layout(Parent.java:1082) at javafx.scene.Scene.doLayoutPass(Scene.java:576) at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2386) at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:321) at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:319) at java.security.AccessController.doPrivileged(Native Method) at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:319) at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:348) at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:479) at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:460) at com.sun.javafx.tk.quantum.QuantumToolkit$13.run(QuantumToolkit.java:327) at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95) at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39) at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112) at java.lang.Thread.run(Thread.java:745) As you can see, it's all JavaFX code on the stack, so this is a little tricky to debug. As such I'm not sure yet if this is a JavaFX bug introduced with 8.0 or an application bug that was masked in JavaFX 2.2 and is now showing up in JavaFX 8. This happens when the managed/visible state of children changes.. but I think it only for the case when all the children become unmanaged. Once it happens JavaFX is crippled and pretty much all layout is broken. Popups (menus) still work and I can exit the application, but all layout in the main window seems to not happen anymore. Manual positioning of nodes still works though. I'll try to isolate a reproducible test case and file a bug report of course. Scott