When a train is about to depart from station controlled by T-signal (station signal), the game crashes (segfault). Both server and client crash. This happens with both British and Swedish pakset. But the swedish server game is full of T-signals, so it crashed almost immediately, while the british sandbox game has only one, so you can see the bug. You can use this save http://server.exp.simutrans.com/debug-saves/one-train-staff.sve and watch the station Osterskar.
This happened to me after the last update, so the culprit will be some of the commits on Apr 9th or 10th.
Found and fixed - thank you for the report.
Seems to be fixed. Thanks