fix

git-svn-id: http://svn.net-core.org/repos/t-engine4@4194 51575b47-30f0-44d4-a5cc-537603b46e54

game/modules/tome/data/talents/misc/npcs.lua

@@ -1319,7 +1319,7 @@ newTalent{
 		if game.level.map:checkEntity(x, y, Map.TERRAIN, "block_move") then return nil end
 
 		local oe = game.level.map(x, y, Map.TERRAIN)
-		if oe.is_volcano then return end
+		if not oe or oe.is_volcano then return end
 
 		local e = Object.new{
 			old_feat = oe,