Hi,
I have Simutrans 110. I was playing the game and I accidentaly loaded a game for different pak. The simutrans crashed. I understand that simutrans won't deal with the savegame from different pak, but I think it shoud test the savegame before it tries to load it. (Generaly in ideal world any application should not crash under any cirkumstances).
pletiplot, base of your idea is right - to prevent loading of wrong game - but a little easier would be separation of games of right pakset during starting of game.