The calculated Chaos guys sent me this email: 'We tested the _a3 version on our full 30 slot server just now and it crashed again. Not soon, but later on when 2-3 points were already capped... If the crash is not caused by the entities, have a look at your physics props so that their "bounding box" isn't inside a wall. Sometimes that can cause stuff like this, even if nothing hits them' So basically, I have some prop_dynamics tied to doors and trains (what Unreal mappers would call "movers") that move through walls and primitives. Could this cause a crash partway into play?