Safety check

@@ -1526,7 +1526,7 @@ function _M:knockback(srcx, srcy, dist, recursive, on_terrain)
 	engine.Actor.knockback(self, srcx, srcy, dist, recursive, on_terrain)
 	if config.settings.tome.smooth_move > 0 then
 		self:resetMoveAnim()
-		self:setMoveAnim(ox, oy, 9, 5)
+		self:setMoveAnim(ox or 0, oy or 0, 9, 5)
 	end
 
 	self:attr("knockback_times", 1)
@@ -1539,7 +1539,7 @@ function _M:pull(srcx, srcy, dist, recursive)
 	engine.Actor.pull(self, srcx, srcy, dist, recursive)
 	if config.settings.tome.smooth_move > 0 then
 		self:resetMoveAnim()
-		self:setMoveAnim(ox, oy, 9, 5)
+		self:setMoveAnim(ox or 0, oy or 0, 9, 5)
 	end
 end
 
@@ -1549,7 +1549,7 @@ function _M:forceMoveAnim(x, y)
 	self:move(x, y, true)
 	if config.settings.tome.smooth_move > 0 then
 		self:resetMoveAnim()
-		self:setMoveAnim(ox, oy, 8, 5)
+		self:setMoveAnim(ox or 0, oy or 0, 8, 5)
 	end
 end
 

@@ -3737,12 +3737,12 @@ newEffect{
 	cancel_on_level_change = true,
 	parameters = { },
 	activate = function(self, eff)
-		eff.leveid = game.zone.short_name.."-"..game.level.level
+		eff.leveid = (game.zone and game.zone.short_name or "??").."-"..(game.level and game.level.level or "??")
 	end,
 	deactivate = function(self, eff)
 		if (eff.allow_override or (self == game:getPlayer(true) and self:canBe("worldport") and not self:attr("never_move"))) and eff.dur <= 0 then
 			game:onTickEnd(function()
-				if eff.leveid == game.zone.short_name.."-"..game.level.level and game.player.can_change_zone then
+				if eff.leveid == (game.zone and game.zone.short_name or "??").."-"..(game.level and game.level.level or "??") and game.player.can_change_zone then
 					game.logPlayer(self, "You are yanked out of this place!")
 					game:changeLevel(1, eff.where or game.player.last_wilderness)
 				end