TFS 1.X+ getNextPosition guidance required

[DemShion]

Hello im trying to use the getNextPosition function without success, heres my code:

function doCharge(cid, targetcid, index)
    local creature = Creature(cid)
    local target = Creature(targetcid)
    local pathToObj = creature:getPathTo(target:getPosition(), 0, 1, true, true)
    if pathToObj ~= false then
        if creature then
          while pathToObj[index] ~= nil do
                print(pathToObj[index])
                local posAux = creature:getPosition():getNextPosition(pathToObj[index])
                print(posAux)
                addEvent(function()
                            creature:teleportTo(posAux, true)
                        end, 200)
                index = index + 1
          end
        end
    end
end

and the msg that prints out to the console is the following:

2
nil
2
nil

also i get the following error in the console:

Lua Script Error: [Main Interface]
in a timer event called from:
(Unknown scriptfile)
attempt to index a nil value
stack traceback:
        [C]: at 0x7ff6709f75a0
        [C]: in function 'teleportTo'
        data/spells/scripts/attack/knight_charge_1.lua:25: in function <data/spells/scripts/attack/knight_charge_1.lua:24>

So my question is, why is "local posAux = creature:getPosition():getNextPosition(pathToObj[index])" evaluating to nil? thanks in advance.