Lua /a don't work

[Kemixe]

Distro:

Lua Script Error: [TalkAction Interface]
data/talkactions/scripts/teleport_ntiles.lua:onSay
data/global.lua:339: attempt to call method 'getTile' (a nil value)
stack traceback:
        [C]: in function 'getTile'
        data/global.lua:339: in function 'getClosestFreePosition'
        data/talkactions/scripts/teleport_ntiles.lua:15: in function <data/talka
ctions/scripts/teleport_ntiles.lua:1>

Lua:

<talkaction words="/a" separator=" " script="teleport_ntiles.lua" />

function onSay(cid, words, param)
    local player = Player(cid)
    if not player:getGroup():getAccess() then
        return true
    end

    local steps = tonumber(param)
    if not steps then
        return false
    end

    local position = player:getPosition()
    position:getNextPosition(player:getDirection(), steps)

    position = player:getClosestFreePosition(position, false)
    if position.x == 0 then
        player:sendCancelMessage("You cannot teleport there.")
        return false
    end

    player:teleportTo(position)
    return false
end

Global.lua

function Player.getClosestFreePosition(self, position, extended)
    if self:getAccountType() >= ACCOUNT_TYPE_GOD then
        return position
    end
    return Creature.getClosestFreePosition(self, position, extended)
end

function Creature.getClosestFreePosition(self, position, extended)
    local usePosition = Position(position)
    local tiles = { usePosition:getTile() }
    local length = extended and 2 or 1
   
    local tile
    for y = -length, length do
        for x = -length, length do
            if x ~= 0 or y ~= 0 then
                usePosition.x = position.x + x
                usePosition.y = position.y + y
               
                tile = usePosition:getTile()
                if tile then
                    tiles[#tiles + 1] = tile
                end
            end
        end
    end
   
    for i = 1, #tiles do
        tile = tiles[i]
        if tile:getCreatureCount() == 0 and not tile:hasProperty(CONST_PROP_BLOCKINGANDNOTMOVEABLE) then
            return tile:getPosition()
        end
    end
    return Position()
end

Help me plz!

 

[Limos]

Update global.lua
https://github.com/otland/forgottenserver/blob/master/data/global.lua

function Position.getTile(self)
     return Tile(self)
end