Index: ps/trunk/binaries/data/mods/public/simulation/components/BuildingAI.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/BuildingAI.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/BuildingAI.js
@@ -357,7 +357,7 @@
 
 		// Copied from UnitAI's MoveToTargetAttackRange.
 		let targetCmpPosition = Engine.QueryInterface(selectedTarget, IID_Position);
-		if (!targetCmpPosition.IsInWorld())
+		if (!targetCmpPosition || !targetCmpPosition.IsInWorld())
 			continue;
 
 		let t = targetCmpPosition.GetPosition();
Index: ps/trunk/binaries/data/mods/public/simulation/components/UnitAI.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/UnitAI.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/UnitAI.js
@@ -4552,7 +4552,7 @@
 	let s = thisCmpPosition.GetPosition();
 
 	let targetCmpPosition = Engine.QueryInterface(target, IID_Position);
-	if (!targetCmpPosition.IsInWorld())
+	if (!targetCmpPosition || !targetCmpPosition.IsInWorld())
 		return false;
 
 	let t = targetCmpPosition.GetPosition();