ERROR: Error in timer on entity 150, IID 37, function MissileHit: TypeError: Engine.QueryInterface(ent, IID_Footprint) is null (2562,[object Object],12.023255509091541)@simulation/components/Attack.js:538 ([object Object],12.023255509091541)@simulation/components/Attack.js:617 ([object Object])@simulation/components/Timer.js:93 ERROR: Error in timer on entity 2006, IID 37, function MissileHit: TypeError: Engine.QueryInterface(ent, IID_Footprint) is null (2562,[object Object],12.88243097346276)@simulation/components/Attack.js:538 ([object Object],12.88243097346276)@simulation/components/Attack.js:617 ([object Object])@simulation/components/Timer.js:93 It's appeared a couple of times since changeset 11886 (on clean svn builds), both times when rock throwers were attacking, although there could have been another cause in either case.