How do I stop zombies from dieing when i test the game?

Every time I place a zombie and then test the game, the zombie dies and I don't know why.

local zombie = script.Parent

for _, script in pairs(zombie.ModuleScripts:GetChildren()) do
if not game.ServerStorage:FindFirstChild(script.Name) then
    script:Clone().Parent = game.ServerStorage
end
end

local AI = require(game.ServerStorage.ROBLOX_ZombieAI).new(zombie)
local DestroyService = require(game.ServerStorage.ROBLOX_DestroyService)


local function clearParts(parent)
for _, part in pairs(parent:GetChildren()) do
    clearParts(part)
end
local delay
if parent:IsA("Part") then
    delay = math.random(5,10)
else
    delay = 11
end
DestroyService:AddItem(parent, delay)
end

zombie.Humanoid.Died:connect(function()
AI.Stop()
math.randomseed(tick())
clearParts(zombie)
script.Disabled = true
end)

local lastMoan = os.time()
math.randomseed(os.time())
while true do
local animationTrack = zombie.Humanoid:LoadAnimation(zombie.Animations.Arms)
animationTrack:Play()
--  local now = os.time()
--  if now - lastMoan > 5 then  
--      if math.random() > .3 then
--          zombie.Moan:Play()
----            print("playing moan")
--          lastMoan = now
--      end
--  end
wait(2)
end