Tue Mar 16, 2021 7:48 pm
The Silent Refectory map has a hidden door between the starting warehouse area and the dining area which is opened by pulling one of the rock switches in the warehouse (sector tag 2). The other side of this door, presumably for multiplayer purposes, is also tagged with a door open action. Both triggers are single-use.
If a player opens the door, goes through, and activates the back side of the open door, it will close, and become permanently shut, potentially making it impossible to progress further (recoverable with cheats in single player, but rather more fatal for co-op).
This bug goes back at least to ZDoom v2.8.1 but is not present in vanilla Hexen (activating the already-open door does nothing originally).