Further fix to correct this issue identified - http://www.elvastower.com/forums/index.php?/topic/35205-crash-after-uncoupling-with-front-coupler/

peternewell · peternewell · commit f9fb52a9cfb5 · 2021-06-04T07:43:37.000+10:00
diff --git a/Source/Orts.Simulation/Simulation/Physics/Train.cs b/Source/Orts.Simulation/Simulation/Physics/Train.cs
@@ -5596,10 +5596,14 @@ public void UpdateCouplerSlack(float elapsedTime)
                     car.CarAhead = null;
                     if (Cars.Count > j) // if not a single loco
                     {
-                        if (j != Cars.Count - 1) // if so, this is the last car, and hence no cars behind it
+                        if (j < Cars.Count - 1) // if > then or =, this is the last car, and hence no further cars behind it
                         {
                             car.CarBehind = Cars[j + 1];
                         }
+                        else
+                        {
+                            car.CarBehind = null;
+                        }
                     }
                     else // if a single loco
                     {

Original file line number	Diff line number	Diff line change
`@@ -5596,10 +5596,14 @@ public void UpdateCouplerSlack(float elapsedTime)`
`5596`	`5596`	`car.CarAhead = null;`
`5597`	`5597`	`if (Cars.Count > j) // if not a single loco`
`5598`	`5598`	`{`
`5599`		`- if (j != Cars.Count - 1) // if so, this is the last car, and hence no cars behind it`
	`5599`	`+ if (j < Cars.Count - 1) // if > then or =, this is the last car, and hence no further cars behind it`
`5600`	`5600`	`{`
`5601`	`5601`	`car.CarBehind = Cars[j + 1];`
`5602`	`5602`	`}`
	`5603`	`+ else`
	`5604`	`+ {`
	`5605`	`+ car.CarBehind = null;`
	`5606`	`+ }`
`5603`	`5607`	`}`
`5604`	`5608`	`else // if a single loco`
`5605`	`5609`	`{`