Are you talking about the problem with NPCs being stuck in a door ? Because that's the only situation when something that fits the description ever happened to me. I mean, when some NPC tried to perform an (melee) attack through an open door, on a target standing on the other side, right next to the door. I think this also happens when the passage is simply blocked by NPCs and sometimes the player. If a player tries to do one of these things (sometimes) the effect is simply 'losing' a turn.