NullReferenceException when delivering message to WP8 app on foreground

System.NullReferenceException was unhandled
  HResult=-2147467261
  Message=Object reference not set to an instance of an object.
  Source=org.jboss.aerogear.unifiedpush.HelloWorld
  StackTrace:
       at AeroGear.Push.Registration.OnPushNotification(String message, IDictionary`2 data)
       at AeroGear.Push.MpnsRegistration.PushChannel_ShellToastNotificationReceived(Object sender, NotificationEventArgs e)
       at Microsoft.Phone.Notification.HttpNotificationChannel.OnToastNotificationReceived(IntPtr blob, UInt32 blobSize)
       at Microsoft.Phone.Notification.HttpNotificationChannel.ChannelHandler(UInt32 eventType, IntPtr blob1, UInt32 int1)
       at Microsoft.Phone.Notification.HttpNotificationChannel.Dispatch(Object threadContext)
       at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
       at System.Threading.ThreadPoolWorkQueue.Dispatch()
       at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
  InnerException: