When the game began. I walked to the right and immediately fell through the floor.
EDIT: Now that I see the map, I think it might be intentional all along! There's a hole where I noclipped though, after all.
EDIT: New problem: I can't close the map! Also, two rooms from the spawn location (the right room in the map), the game became INCREDIBLY laggy! The lag stopped when I went back, however.