Drop a GridPane, and add a Button into it.
Select the Button, and from the Layout section set the rowSpane property to REMAINING.
undo it (ctrl-z).
The following exception is raised:


Exception in thread "JavaFX Application Thread" java.lang.AssertionError
at com.oracle.javafx.scenebuilder.kit.metadata.property.value.IntegerPropertyMetadata.castValue(IntegerPropertyMetadata.java:59)
at com.oracle.javafx.scenebuilder.kit.metadata.property.value.IntegerPropertyMetadata.castValue(IntegerPropertyMetadata.java:41)
at com.oracle.javafx.scenebuilder.kit.metadata.property.value.SingleValuePropertyMetadata.setValueObject(SingleValuePropertyMetadata.java:139)
at com.oracle.javafx.scenebuilder.kit.editor.job.ModifyObjectJob.undo(ModifyObjectJob.java:80)
at com.oracle.javafx.scenebuilder.kit.editor.job.ModifySelectionJob.undo(ModifySelectionJob.java:89)
at com.oracle.javafx.scenebuilder.kit.editor.JobManager.undoJob(JobManager.java:170)
at com.oracle.javafx.scenebuilder.kit.editor.JobManager.undo(JobManager.java:107)
at com.oracle.javafx.scenebuilder.kit.editor.EditorController.undo(EditorController.java:579)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$UndoActionController.perform(MenuBarController.java:970)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.handleOnActionMenu(MenuBarController.java:763)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.access$300(MenuBarController.java:79)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$9.handle(MenuBarController.java:756)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$9.handle(MenuBarController.java:752)
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)