Merge pull request #975 from Csantucci/Fix-crash-when-AI-train-dissolves

Bug fix for https://bugs.launchpad.net/or/+bug/2076133 Crash when AI train dissolves near camera

Author: Csantucci

Source/RunActivity/Viewer3D/Lights.cs

@@ -293,7 +293,7 @@ bool UpdateState()
             bool newCarIsFirst = !Car.Lights.IgnoredConditions[1] && (locomotiveFlipped ^ locomotiveReverseCab ? Car.Train?.LastCar : Car.Train?.FirstCar) == Car;
             bool newCarIsLast = !Car.Lights.IgnoredConditions[1] && (locomotiveFlipped ^ locomotiveReverseCab ? Car.Train?.FirstCar : Car.Train?.LastCar) == Car;
             // Penalty
-			bool newPenalty = !Car.Lights.IgnoredConditions[2] && Car.Train.TrainType != Train.TRAINTYPE.AI
+			bool newPenalty = !Car.Lights.IgnoredConditions[2] && Car.Train != null && Car.Train.TrainType != Train.TRAINTYPE.AI
                 && leadLocomotive != null && leadLocomotive.TrainBrakeController.EmergencyBraking;
             // Control
             bool newCarIsPlayer = !Car.Lights.IgnoredConditions[3] && Car.Train != null && (Car.Train == Viewer.PlayerTrain || Car.Train.TrainType == Train.TRAINTYPE.REMOTE);