There was a null pointer exception related to going into/leaving third person camera and the arrow annotation.

racevisionGame/src/main/java/visualiser/Controllers/RaceViewController.java

@@ -441,7 +441,10 @@ public class RaceViewController extends Controller {
 
     private void removeThirdPersonAnnotations() {
         viewSubjects.remove(nextMarkArrow);
-        arrowToNextMark.stop();
+        if (arrowToNextMark != null) {
+            arrowToNextMark.stop();
+        }
+
     }
 
     /**