Every time the legendary city Deorcnysse spawns in sandbox game, with the accompanying world quest, there seems to be two bugs.

1. The city has no garrison - you can just walk right in and take it over.

2. Claiming the city makes it impossible to continue the game as the Next Turn function stops working.

I assume there's something broken in the quest structure and that the city is supposed to be heavily guarded, but these guards doesn't spawn. So taking the city without fighting these guards means that game does not progress to the next step of the quest, thus locking the game.