I'm trying to login Facebook with [Prime31]WinPhoneSocialNetwork plugin! After built, I run and get this error! Please help! A first chance exception of type 'System.NullReferenceException' occurred in P31WinPhoneHelpers.DLL NullReferenceException: Object reference not set to an instance of an object. at P31WinPhoneHelpers.UIHelper.beginExecute(Action action) at Prime31.WinPhoneSocialNetworking.FacebookAccess.login(String[] permissions, Action`2 completionHandler) at test.Click_Login() at UnityEngine.Events.InvokableCall.Invoke(Object[] args) at UnityEngine.Events.InvokableCallList.Invoke(Object[] parameters) at UnityEngine.Events.UnityEventBase.Invoke(Object[] parameters) at UnityEngine.Events.UnityEvent.Invoke() at UnityEngine.UI.Button.Press() at UnityEngine.UI.Button.OnPointerClick(PointerEventData eventData) at UnityEngine.EventSystems.ExecuteEvents.Execute(IPointerClickHandler handler, BaseEventData eventData) at UnityEngine.EventSystems.ExecuteEvents.Execute[T](GameObject target, BaseEventData eventData, EventFunction`1 functor) (Filename: TODO Line: 0)