Lua Erro Script

[Gaber Zen]

hello everyone

I got Erro There
otx-8.60

[Error - CreatureScript Interface]
data/creaturescripts/scripts/levels.luanAdvance
Description:
data/creaturescripts/scripts/levels.lua:60: attempt to index a nil value
stack traceback:
data/creaturescripts/scripts/levels.lua:60: in function <data/creaturescripts/scripts/levels.lua:24>

--[[ / / / / / / / / / / / / / / / / / / / / / /
               Advanced OnAdvance
        The Best OnAdvance Creaturescript
        Scripted by Cybermaster
         @The Forgotten Server
           OTLand.net
/ / / / / / / / / / / / / / / / / / / / / / ]]--


local config =
    {
        --message, distance shoot effect
        [0] = {'+Fist', 38},
        [1] = {'+Mace', 26},
        [2] = {'+Swrd', 24},
        [3] = {'+Axe', 25},
        [4] = {'+Dist', 2},
        [5] = {'+Def', 11},
        [6] = {'+Fish', 12},
        [7] = {'+ML', 35},
        [8] = {'+LvL', 39}
    }

function onAdvance(cid, skill, oldlevel, newlevel)
    if skill == SKILL__LEVEL then
        doCreatureAddHealth(cid, getCreatureMaxHealth(cid) - getCreatureHealth(cid))
        doCreatureAddMana(cid, getCreatureMaxMana(cid) - getCreatureMana(cid))
    end

    local p = getThingPos(cid)
    local positions =
    {    --do not touch
        [1] = {
            {x=p.x+1,y=p.y,z=p.z}, 100, 900
        },
        [2] = {
            {x=p.x+1,y=p.y+1,z=p.z}, 200, 980
        },
        [3] = {
            {x=p.x,y=p.y+1,z=p.z}, 300, 1060
        },
        [4] = {
            {x=p.x-1,y=p.y+1,z=p.z}, 400, 1140
        },
        [5] = {
            {x=p.x-1,y=p.y,z=p.z}, 500, 1220
        },
        [6] = {
            {x=p.x-1,y=p.y-1,z=p.z}, 600, 1300
        },
        [7] = {
            {x=p.x,y=p.y-1,z=p.z}, 700, 1380
        },
        [8] = {
            {x=p.x+1,y=p.y-1,z=p.z}, 800, 1460
        }
    }
      
    for i = 1, 8 do
        addEvent(doSendDistanceShoot, positions[i][2], positions[i][1], p, config[skill][2])
        addEvent(doSendDistanceShoot, positions[i][3], positions[i][1], p, config[skill][2])
        addEvent(doSendDistanceShoot, positions[i][4], positions[i][1], p, config[skill][2])
        addEvent(doSendDistanceShoot, positions[i][5], positions[i][1], p, config[skill][2])
    end
    
    doSendAnimatedText(p, config[skill][1].." ["..newlevel.."]", TALKTYPE_ORANGE_2)
    doPlayerSave(cid, true)   
    return true
end