That line corresponds to the following, specifically the slaangenerdiet2 part:
Code:
monitor_event FactionTurnStart FactionType teutonic_order
and I_CompareCounter dieter = 3
and not I_SettlementOwner Dietershafen = teutonic_order
and not I_SettlementUnderSiege Dietershafen
if I_CharacterExists slaangenerdiet
and not I_SettlementOwner Dietershafen = teutonic_order
siege_settlement slaangenerdiet, Dietershafen, maintain
end_if
if I_CharacterExists slaangenerdiet2
and not I_SettlementOwner Dietershafen = teutonic_order
siege_settlement slaangenerdiet2, Dietershafen, maintain
end_if
set_counter dieter 4
terminate_monitor
end_monitor
What seems to be happening is they take the city and you lose the game. I dunno what that is about, I haven't touched that part of the campaign_script, or edited any generals or spawns or settlements there, so it theoretically should be a bug in the main beta, too. Have you tried reloading it? Does it happen when ending a turn? Personally I want to get rid of like 98% of the spawn scripts at some point, but right now the only thing I've changed in the campaign_script is the turn 1 massive war. Maybe someone like Gigantus could figure out what's going wrong. Try reloading your save and seeing if it crashes again, and if so, try turning the fog of war off with the toggle_fow command and taking a look at Dieterschafen and who owns it, and if Chaos is united under Slaanesh or some other oddity.