NPCs do not load animation?

Whenever I try to load an animation into an NPC, it says "Object must be in Workspace before loading animation."This is the script( which is in the npc model)

hitt = false
function Hit(hit)
    local human = hit.Parent:FindFirstChild("Humanoid")
    if not hitt and hit.Parent.Name ~= script.Parent.Name and script.Parent:FindFirstChild("Left Arm") and script.Parent:FindFirstChild("Right Arm") and human and hit.Parent:FindFirstChild("IsSoldier") and hit.Parent.IsSoldier.Value == true then
        hitt = true
            local AnimController = Instance.new("AnimationController",script.Parent)
            local animation = Instance.new("Animation",script.Parent.Humanoid)
            animation.AnimationId = "http://www.roblox.com/asset?ID=359602146"
            local animTrack = AnimController:LoadAnimation(animation)
            animTrack:Play() -- play animation
        human:TakeDamage(math.random(20,30))
        wait(.8)
        animation:Destroy()
        AnimController:Destroy()
        hitt = false
    end
end


script.Parent["Left Arm"].Touched:connect(Hit)
script.Parent["Right Arm"].Touched:connect(Hit)

As you can see, the animation is created in the script and placed into the humanoid. P.S. The model usually attacks someone(using this script) shortly after it is cloned from the serverstorage to the workspace(about 1 second)