Argument 1 missing or nil on a animation of my tools, How i can fix it?

When i start the server this error come "Argument 1 missing or nil" how i can fix it?

Localscript inside the tool

Player = game.Players.LocalPlayer

game.Workspace:WaitForChild()

stone = script.Parent

Anim = game.Lighting.Animations.StoneHold
Track = Player.Character:WaitForChild("Humanoid"):LoadAnimation(Anim)

stone.Equipped:Connect(function()
    Track:Play()
    Track.Looped = true
end)

stone.Unequipped:Connect(function()
    Track:Stop()

end)