Сделано

Trolleybus/Trolleybus/DrawingTrolleybus.cs

@@ -53,6 +53,10 @@ namespace Trolleybus
         }
         public void SetPosition(int x, int y)
         {
+            if (EntityTrolleybus == null)
+            {
+                return;
+            }
             if (x < 0 || y < 0 || x + _trolleybusWidth >= _pictureWidth || y + _trolleybusHeight >= _pictureHeight)
                 x = y = 10;
             _startPosX = x;