Hello, I've uploaded a Session without Rollingstock and tested. The Client TS12 crashed too. The Error must be on the Map - not in the Session, maybe at the Newnes Iron Mine, because the gondolas (in Session V1e) does derail in Editor.
When I save the Route as my own (after switching a junction), then I have a missing KUID. It is the Cementwork kuid2:67794:28005:8, but this kuid is not exisiting. The highest is 28005:7 for TC and TS2010. The Entry in config.txt was 506 (Route), but this was deleted - but in the route.obj or route.trk too?