NullPointerException when opening advance edit or edit on already created event.

[DBloodworth95]

Not sure why this is happening but I'm getting the following exception thrown when trying to open the "Advanced edit" or "Edit" feature for events. I want to be able to create recurring events.

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException at jfxtras.internal.scene.control.skin.agenda.icalendar.base24hour.popup.EditRecurrenceRuleVBox.getFormatter(EditRecurrenceRuleVBox.java:151) at jfxtras.internal.scene.control.skin.agenda.icalendar.base24hour.popup.EditRecurrenceRuleVBox.access$000(EditRecurrenceRuleVBox.java:88) at jfxtras.internal.scene.control.skin.agenda.icalendar.base24hour.popup.EditRecurrenceRuleVBox$2.toString(EditRecurrenceRuleVBox.java:844) at jfxtras.internal.scene.control.skin.agenda.icalendar.base24hour.popup.EditRecurrenceRuleVBox$2.toString(EditRecurrenceRuleVBox.java:841) at javafx.controls/javafx.scene.control.skin.ComboBoxListViewSkin.updateDisplayText(ComboBoxListViewSkin.java:449) at javafx.controls/javafx.scene.control.skin.ComboBoxListViewSkin.updateDisplayNode(ComboBoxListViewSkin.java:348) at javafx.controls/javafx.scene.control.skin.ComboBoxListViewSkin.getDisplayNode(ComboBoxListViewSkin.java:257) at javafx.controls/javafx.scene.control.skin.ComboBoxBaseSkin.updateDisplayArea(ComboBoxBaseSkin.java:289) at javafx.controls/javafx.scene.control.skin.ComboBoxListViewSkin.updateButtonCell(ComboBoxListViewSkin.java:467) at javafx.controls/javafx.scene.control.skin.ComboBoxListViewSkin.<init>(ComboBoxListViewSkin.java:163) at javafx.controls/javafx.scene.control.ComboBox.createDefaultSkin(ComboBox.java:447) at javafx.controls/javafx.scene.control.Control.doProcessCSS(Control.java:897) at javafx.controls/javafx.scene.control.Control.access$000(Control.java:83) at javafx.controls/javafx.scene.control.Control$1.doProcessCSS(Control.java:89) at javafx.controls/com.sun.javafx.scene.control.ControlHelper.processCSSImpl(ControlHelper.java:67) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1404) at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81) at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127) at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1404) at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81) at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127) at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1404) at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81) at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127) at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1404) at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81) at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127) at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1404) at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81) at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127) at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1404) at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81) at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127) at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1404) at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81) at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127) at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1404) at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81) at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127) at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100) at javafx.controls/com.sun.javafx.scene.control.ControlHelper.superProcessCSSImpl(ControlHelper.java:63) at javafx.controls/com.sun.javafx.scene.control.ControlHelper.superProcessCSS(ControlHelper.java:55) at javafx.controls/javafx.scene.control.Control.doProcessCSS(Control.java:900) at javafx.controls/javafx.scene.control.Control.access$000(Control.java:83) at javafx.controls/javafx.scene.control.Control$1.doProcessCSS(Control.java:89) at javafx.controls/com.sun.javafx.scene.control.ControlHelper.processCSSImpl(ControlHelper.java:67) at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147) at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9515) at javafx.graphics/javafx.scene.Scene.doCSSPass(Scene.java:583) at javafx.graphics/javafx.scene.Scene.preferredSize(Scene.java:1770) at javafx.graphics/javafx.scene.Scene$2.preferredSize(Scene.java:394) at javafx.graphics/com.sun.javafx.scene.SceneHelper.preferredSize(SceneHelper.java:66) at javafx.graphics/javafx.stage.Window$12.invalidated(Window.java:1098) at javafx.base/javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:110) at javafx.base/javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:145) at javafx.graphics/javafx.stage.Window.setShowing(Window.java:1186) at javafx.graphics/javafx.stage.Window.show(Window.java:1201) at javafx.graphics/javafx.stage.Stage.show(Stage.java:277) at jfxtras.scene.control.agenda.icalendar.ICalendarAgenda.lambda$new$10(ICalendarAgenda.java:546) at jfxtras.scene.control.agenda.icalendar.ICalendarAgenda.lambda$new$17(ICalendarAgenda.java:626) at javafx.base/com.sun.javafx.collections.ListListenerHelper$Generic.fireValueChangedEvent(ListListenerHelper.java:329) at javafx.base/com.sun.javafx.collections.ListListenerHelper.fireValueChangedEvent(ListListenerHelper.java:73) at javafx.base/javafx.collections.ObservableListBase.fireChange(ObservableListBase.java:233) at javafx.base/javafx.collections.ListChangeBuilder.commit(ListChangeBuilder.java:482) at javafx.base/javafx.collections.ListChangeBuilder.endChange(ListChangeBuilder.java:541) at javafx.base/javafx.collections.ObservableListBase.endChange(ObservableListBase.java:205) at javafx.base/javafx.collections.ModifiableObservableListBase.add(ModifiableObservableListBase.java:155) at java.base/java.util.AbstractList.add(AbstractList.java:111) at jfxtras.internal.scene.control.skin.agenda.base24hour.DayBodyPane.lambda$setupMouseDrag$6(DayBodyPane.java:185) at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86) at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238) at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191) at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74) at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54) at javafx.base/javafx.event.Event.fireEvent(Event.java:198) at javafx.graphics/javafx.scene.Scene$MouseHandler.process(Scene.java:3876) at javafx.graphics/javafx.scene.Scene$MouseHandler.access$1300(Scene.java:3604) at javafx.graphics/javafx.scene.Scene.processMouseEvent(Scene.java:1874) at javafx.graphics/javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2613) at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:397) at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295) at java.base/java.security.AccessController.doPrivileged(Native Method) at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(GlassViewEventHandler.java:434) at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:395) at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:433) at javafx.graphics/com.sun.glass.ui.View.handleMouseEvent(View.java:556) at javafx.graphics/com.sun.glass.ui.View.notifyMouse(View.java:942) at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method) at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication.lambda$runLoop$11(GtkApplication.java:277) at java.base/java.lang.Thread.run(Thread.java:834)