Playing 9.11
Shadow halls L1.. I have cleaned the level. The game says there's a vault and 4 baddies left. Searched, no vault. Used a terminal to open the level map. It reveals an area with no doors and a white block. Moving along side the walls, I can see a sector defined area with lines.

My character is a marine with the skill to see enemies 2 hexes away. no enemies.

I stopped the game and saved it.

Maybe the baddies destroyed all the locked doors?
and sometimes monsters fight others, and if they do DoT they may very rarely kill all each other.

It's a bug. The level didn't complete it's build before it stopped.