How to implement FindPartOnRayWithIgnoreList into this bot script?

Hello there, scripters! I'm having a problem with implementing FindPartOnRayWithIgnoreList into my pathfinding AI. When ever I try to do it in the script it throws an error: Unable to cast value to Objects. When I put it back to FindPartOnRay in the script, it is fully working again, but there is no ignore list for the AI. Here's the code

local maxDistance = 5000

local canWander = true
local WanderX, WanderZ = 20, 20

function getHumanoid(model)
    for _, v in pairs(model:GetChildren()) do
        if v:IsA'Humanoid' then
            return v
        end
    end
end

local ai = script.Parent
local human = getHumanoid(ai)
local hroot = ai.HumanoidRootPart
local zspeed = hroot.Velocity.magnitude


local pfs = game:GetService("PathfindingService")

function GetPlayerNames()
    local players = game:GetService('Players'):GetChildren()
    local name = nil
    for _, v in pairs(players) do
        if v:IsA'Player' then
            name = tostring(v.Name)
        end
    end
    return name
end

function GetPlayersBodyParts(t)
    local torso = t
    if torso then
        local figure = torso.Parent
        for _, v in pairs(figure:GetChildren()) do
            if v:IsA'Part' then
                return v.Name
            end
        end
    else
        return "HumanoidRootPart"
    end
end

function GetTorso(part)
    local chars = game.Workspace:GetChildren()
    local torso = nil
    for _, v in pairs(chars) do
        if v:IsA'Model' and v ~= script.Parent and v.Name == GetPlayerNames() then
            local charRoot = v:FindFirstChild'HumanoidRootPart'
            if (charRoot.Position - part).magnitude < maxDistance then
                torso = charRoot
            end
        end
    end
    return torso
end

-- no touchy
local path
local waypoint
local oldpoints
local isWandering = 0

if canWander then
    spawn(function()
        while isWandering == 0 do
            isWandering = 1
            local desgx, desgz = hroot.Position.x + math.random(-WanderX, WanderX), hroot.Position.z + math.random(-WanderZ, WanderZ)
            human:MoveTo(Vector3.new(desgx, 0, desgz))
            wait(math.random(4, 6))
            isWandering = 0
        end
    end)
end

while wait() do
    local enemytorso = GetTorso(hroot.Position) 
    if enemytorso ~= nil then -- if player detected
        isWandering = 1
        local function checkw(t)
            local ci = 3
            if ci > #t then
                ci = 3
            end
            if t[ci] == nil and ci < #t then
                repeat
                    ci = ci + 1
                    wait()
                until t[ci] ~= nil
                return Vector3.new(1, 0, 0) + t[ci]
            else
                ci = 3
                return t[ci]
            end
        end

        path = pfs:CreatePath()
        path:ComputeAsync(hroot.Position, enemytorso.Position)
        waypoint = path:GetWaypoints()
        oldpoints = waypoint
        local connection;

        local direct = Vector3.FromNormalId(Enum.NormalId.Front)
        local ncf = hroot.CFrame * CFrame.new(direct)
        direct = ncf.p.unit
        local rootr = Ray.new(hroot.Position, enemytorso.Position)
        local phit, ppos = game.Workspace:FindPartOnRayWithIgnoreList(rootr, ai)

        if path and waypoint or checkw(waypoint) then
            if checkw(waypoint) ~= nil and checkw(waypoint).Action == Enum.PathWaypointAction.Walk then
                human:MoveTo( checkw(waypoint).Position )
                human.Jump = false
            end

            if checkw(waypoint) ~= nil and checkw(waypoint).Action == Enum.PathWaypointAction.Jump then
                wait(2)
                human.Jump = true
                wait(0.5)
                human:MoveTo( checkw(waypoint).Position )
            else
                human.Jump = false
            end

        else
            for i = 3, #oldpoints do
                human:MoveTo( oldpoints[i].Position )   
            end
        end
    elseif enemytorso == nil and canWander then -- if player not detected
        isWandering = 0
        path = nil
        waypoint = nil
        human.MoveToFinished:Wait()
    end
end

print("_char is chosen, subject is pathfinding...")

I'm pretty sure this one line breaks the whole script,

local phit, ppos = game.Workspace:FindPartOnRayWithIgnoreList(rootr, ai)

Any ideas? What is going wrong?

I've tried the workspace:Raycast but it dosen't work.