ToME: the Tales of Maj'Eyal

I've killed everything on the level, but none of the doors to the central staircase open. Bug, or is there some gimmick I'm missing? The walls are also dig-proof, and I can't control-phase onto the stairs.

Hum, can you send me the save please ?

Sent!

Is this still an issue? I am also stuck now in 15b

I had that bug happen to me, but I've got a posterior game where it worked fine so I think it's been fixed already.
If it's the same save you're using, you'd probably best recall out, save and exit, delete tannen-tower from your save folder and go again.

I didn't know i could delete specific dungeons from my save, and I didn't know what would happen if I recalled out, so I did ctrl-alt-delete, reloaded the autosave (beginning of said level), and went from there without a hitch.