My boss battle script doesn't work? And I need help with it quickly (I use BodyGyro in HRP)

Why doesn't my boss battle work? I used Body Gyro and this script:

local Humanoid = script.Parent:WaitForChild("Humanoid")

local HumanoidRootPart = script.Parent:WaitForChild("HumanoidRootPart")

local WalkRange = 20

local LavaBallSpeed = 45

local Closest = nil

spawn(function()

while true do

wait()

if Closest _= nil then

HumanoidRootPart.BodyGyro.CFrame = CFrame.new(HumanoidRootPart.Position,Vector3.new(Closest.Character.HumanoidRootPart.Position.X,HumanoidRootPart.Position.Y,Closest.Character.HumanoidRootPart.Position.Z))

end

end

end)

while true do

wait(2)

local RandomValue = math.random(0,10)

local List = ()

for i,v in pairs(game.Players:GetChildren()) do

if v. and v.Character then

local Distance = (HumanoidRootPart.Position - v.Character.HumanoidRootPart.Position).Magnitude

table.insert(List,(v,Distance))

end

end

table.sort(List,function(A,B)

return A[2] <= B[2]

end)

if #List >= 1 then

Closest = List[1][1]

if RandomValue > 0 and RandomValue < 6 then

local RandomWalkPosition = Vector3.new(math.random(-WalkRange,WalkRange),0,math.random(-WalkRange,WalkRange))

Humanoid:MoveTo(HumanoidRootPart.Position+RandomWalkPosition)

else

local Lavaball = Instance.new("Part")

Lavaball.Anchored = false

Lavaball.Shape = "Ball"

Lavaball.Size = Vector3.new(4,4,4)

Lavaball.TopSurface = Enum.SurfaceType.Smooth

Lavaball.BottomSurface = Enum.SurfaceType.Smooth

Lavaball.Material = Enum.Material.CorrodedMetal

Lavaball.BrickColor = BrickColor.new("Maroon")

Lavaball.CFrame = HumanoidRootPart.CFrame*CFrame.new(0,0,-10)

Lavaball.Parent = workspace

Lavaball.CanCollide = false

local BV = Instance.new("BodyVelocity")

BV.MaxForce = Vector3.new(100000,100000,100000)

local Origin = HumanoidRootPart.Position

BV.Velocity = (List[1][1].Character.HumanoidRootPart.Position - Origin).unit * LavaBallSpeed

BV.Parent = Lavaball

spawn(function()

wait(1)

Lavaball.Touched:Connect(function(Hit)

if Hit and Hit.Parent and Hit.Parent:FindFirstChild("Humanoid") then

Hit.Parent.Humanoid:TakeDamage(25)

end

Lavaball:Destroy()

end)

end)

wait(2)

end

end

end

(At my game on the page it says "This game doesn't function" something like that.) I visit the website but still don't know how to fix my script. Can someone help me with this or reply with the script that works?

Thank you so much!