How to make the reflectance go back ?

What error i get is attempt to index upvalue 'target' (a nil value) it makes the character reflectance random but doesn't make it go back the hell ? Ignore the other lines, but the math random lines and the last one with reflectance ? Why does the first 6 lines of math random work but others on the end not ? example:

local sp = script.Parent
local turret = sp.Gun
local target = nil
local ready = true
local targettable = {}
local set = require(script.Settings)

game:GetService('RunService').Stepped:connect(function()
    targettable = {}
    for _,plr in pairs(game.Players:GetChildren()) do
        if plr:DistanceFromCharacter(turret.Position) <= set.radius and plr.TeamColor ~= set.allycolor and plr.Character.Humanoid.Health >0 then
            table.insert(targettable,plr)
        else
            target = nil
            targettable = {}
        end
    end
    if table.getn(targettable)>0 then
        target = targettable[math.random(1,#targettable)]
    elseif table.getn(targettable) == 0 then
        target = nil
    end
    if target ~= nil then
        if ready == true then
            ready = false
            Laser(turret.Position,target.Character.Torso.Position)
            target.Character.Humanoid:TakeDamage(set.damage)
            target.Character:findFirstChild("Head").Reflectance =(math.random(0.2,1))
            target.Character:findFirstChild("Torso").Reflectance =(math.random(0.2,1))
            target.Character:findFirstChild("Right Arm").Reflectance =(math.random(0.2,1))
            target.Character:findFirstChild("Right Leg").Reflectance =(math.random(0.2,1))
            target.Character:findFirstChild("Left Arm").Reflectance =(math.random(0.2,1))
            target.Character:findFirstChild("Left Leg").Reflectance =(math.random(0.2,1))
            target.Character.Humanoid.WalkSpeed = 8
            turret.Fire:Play()
            wait(set.shotcooldown)
            ready = true
        end
    end
    target = nil
end)

function Laser(StartPosition,TargetPosition,Hit)
    turret.Material = Enum.Material.Neon
    local ray = Instance.new("Part")
    ray.TopSurface = Enum.SurfaceType.Smooth
    ray.BottomSurface = Enum.SurfaceType.Smooth
    ray.FormFactor = Enum.FormFactor.Custom
    ray.Size = Vector3.new(0.5, 0.2, 0.2)
    ray.CanCollide = false
    ray.Locked = true
    ray.Anchored = true
    ray.Name = "Laser"
    ray.BrickColor = BrickColor.new("Cyan")
    ray.Material = Enum.Material.Neon
    ray.Size = Vector3.new(0.0, 0.5, 0.2)
    local raymesh = Instance.new("SpecialMesh")
    raymesh.Name = "Mesh"
    raymesh.MeshType = Enum.MeshType.Brick
    raymesh.Scale = Vector3.new(0.2, 0.2, 1)
    raymesh.Offset = Vector3.new(0, 0, 0)
    raymesh.VertexColor = Vector3.new(1, 1, 1)
    raymesh.Parent = ray
    local Vec = (TargetPosition - StartPosition)
    local Distance = Vec.magnitude
    local Direction = Vec.unit
    local PX = (StartPosition + (0.25 * Distance) * Direction)
    local PY = (StartPosition + (0.5 * Distance) * Direction)
    local PZ = (StartPosition + (0.75 * Distance) * Direction)
    local DX = (StartPosition - PX).magnitude
    local DY = (PX - PY).magnitude
    local DZ = (PY - PZ).magnitude
    local Limit = 2
    local AX = (PX + Vector3.new(math.random(math.max(-Limit, (-0.21 * DX)), math.min(Limit, (0.21 * DX))),math.random(math.max(-Limit, (-0.21 * DX)),math.min(Limit, (0.21 * DX))), math.random(math.max(-Limit, (-0.21 * DX)), math.min(Limit, (0.21 * DX)))))
    local AY = (PY + Vector3.new(math.random(math.max(-Limit, (-0.21 * DY)), math.min(Limit, (0.21 * DY))),math.random(math.max(-Limit, (-0.21 * DY)),math.min(Limit, (0.21 * DY))), math.random(math.max(-Limit, (-0.21 * DY)), math.min(Limit, (0.21 * DY)))))
    local AZ = (PZ + Vector3.new(math.random(math.max(-Limit, (-0.21 * DZ)), math.min(Limit, (0.21 * DZ))),math.random(math.max(-Limit, (-0.21 * DZ)),math.min(Limit, (0.21 * DZ))), math.random(math.max(-Limit, (-0.21 * DZ)), math.min(Limit, (0.21 * DZ)))))
    local Rays = {
        {Distance = (AX - StartPosition).magnitude, Direction = CFrame.new(StartPosition, AX)},
        {Distance = (AY - AX).magnitude, Direction = CFrame.new(AX, AY)},
        {Distance = (AZ - AY).magnitude, Direction = CFrame.new(AY, AZ)},
        {Distance = (TargetPosition - AZ).magnitude, Direction = CFrame.new(AZ, TargetPosition)},
    }
    for i, v in pairs(Rays) do
        local Ray = ray:Clone()
        local Mesh = Ray.Mesh
        Mesh.Scale = (Vector3.new(0.15, 0.15, (v.Distance / 1)) * 5)
        Ray.CFrame = (v.Direction * CFrame.new(0, 0, (-0.5 * v.Distance)))
        game:GetService("Debris"):AddItem(Ray, (0.1 / (#Rays - (i - 1))))
        Ray.Parent = workspace
    end
    turret.Material = Enum.Material.Neon
end