Add null check for some UI components.

Assets/Cryville/Crtr/NetworkTaskWorkerTicker.cs

@@ -15,7 +15,9 @@ namespace Cryville.Crtr {
 		static Color _tickColor2 = new Color(1, 1, 1, .8f);
 		static Color _suspendedColor = new Color(1, 0, 0, 1);
 		void Update() {
-			switch (Game.NetworkTaskWorker.TickBackgroundTasks()) {
+			var status = Game.NetworkTaskWorker.TickBackgroundTasks();
+			if (_image == null) return;
+			switch (status) {
 				case WorkerStatus.Idle:
 					_image.color = _idleColor;
 					timer = 0f;