Error popping up after zombie is killed

Help and Feedback Scripting Support
#1

Hello Devforum! I have been making a zombie recently, but I have run into an interesting error that I have found really annoying. Once you kill a zombie, an error appears saying that a part of the zombie is not a valid member.

Example:

image
image712×30 13 KB

This is a short video of what happens:
https://gyazo.com/d231f0d512c55f0dda389736b114d36d

I think this error appears because I have a while loop for every second that fires a function from the module of the zombie, so I made the zombie get destroyed quicker, but the error still occurred. It might have something to do with my module script or my main script, but I am not sure where it goes wrong.

Script:

local pathfindingservice = game:GetService("PathfindingService")
local collectionservice = game:GetService("CollectionService")
local serverstorage = game:GetService("ServerStorage")

local zombies = {}
local serverzombie = serverstorage:WaitForChild("Zombie")

local zombiemodule = require(game.ReplicatedStorage.ZombieModule)

function taghuman(instance)
	local human = instance:FindFirstChildWhichIsA("Humanoid")
	if human then
		collectionservice:AddTag(human, "Human")		
	end
end

function tagzombie(instance)
	local zombie = instance:FindFirstChild("Zombie")
	if zombie then
		collectionservice:AddTag(zombie, "Zombie")
	end
end

game.Workspace.ChildAdded:Connect(taghuman)
print("tagged human")
game.Workspace.ZombieFolder.ChildAdded:Connect(tagzombie)
print("tagged zombie")

while true do
	local zombieclone = serverzombie:Clone()
	zombieclone.UpperTorso.CFrame = game.Workspace.Spawners.Spawner.CFrame
	zombieclone.Parent = game.Workspace.ZombieFolder
	tagzombie(zombieclone)
	print("tagged zombie")
	zombiemodule.healthfunction(zombieclone)
	print("Health gui in action")
	zombiemodule.findtarget(zombieclone)
	print("Found target for "..zombieclone.Name)
	coroutine.wrap(function()
		while wait(1) do
			if zombieclone then
				zombiemodule.movementcontrol(zombieclone)				
			end
		end		
	end)()
	wait(5)
end


function initialize()
	for i, v in pairs(game:GetChildren()) do
		taghuman(v)
		print("tagged human")
	end	
end

initialize()

Module:

local module = {}

local collectionservice = game:GetService("CollectionService")

local pathfindingservice = game:GetService("PathfindingService")

module.findtarget = function(zombie)
	local humans = collectionservice:GetTagged("Human")
	local zomhumroot = zombie.HumanoidRootPart
	local dist = 1000
	local target = nil
	for i, human in pairs(game.Workspace:GetChildren()) do
		if human:FindFirstChild("Humanoid") and human:FindFirstChild("HumanoidRootPart") then
			local humanoid = human:FindFirstChild("Humanoid")
			local humroot = human:FindFirstChild("HumanoidRootPart")
			if humanoid and humroot and human ~= zombie then
				if humanoid.Health > 0 then 
					if (zomhumroot.Position - humroot.Position).magnitude < dist then
						dist = (zomhumroot.Position - humroot.Position).magnitude
						target = humroot
					end
				end
			end
		end
	end
	return target
end

module.movementcontrol = function(zombie)
	local zomhumroot = zombie.HumanoidRootPart
	local zomanoid = zombie.Zombie
	local anim = zomanoid.Walk
	local anim2 = zomanoid.Attack
	local anim3 = zomanoid.Idle
	local loadanim = zomanoid:LoadAnimation(anim)
	local loadanim2 = zomanoid:LoadAnimation(anim2)
	local loadanim3 = zomanoid:LoadAnimation(anim3)
	local humroot = module.findtarget(zombie)
	if humroot then
		zomanoid:MoveTo(humroot.Position, humroot)
		loadanim:Play()
		if (zomhumroot.Position - humroot.Position).magnitude < 5 then
			loadanim2:Play()
			humroot.Parent.Humanoid:TakeDamage(15)
		end
	else
		zomanoid:MoveTo(zomhumroot.Position + Vector3.new(math.random(-50,50),0, math.random(-50,50)), game.Workspace.Ground)
		loadanim:Stop()
		loadanim3:Play()
		wait(3)
		loadanim3:Stop()
		loadanim:Play()
	end
end

module.healthfunction = function(zombie)
	local healthgui = zombie.Head:FindFirstChild("HealthGui")
	local zomanoid = zombie:FindFirstChild("Zombie")


	zomanoid:GetPropertyChangedSignal("Health"):Connect(function()
		local healthchange = zomanoid.Health/zomanoid.MaxHealth
		local healthcolor = Color3.fromRGB(255,0,0):Lerp(Color3.fromRGB(60,255,0),healthchange)
		healthgui.Health.Meter:TweenSize(UDim2.new(healthchange,0,1,0),"In","Linear",1)
		healthgui.Health.Meter.BackgroundColor3 = healthcolor
		if zomanoid.Health <= 0 then
			wait(1)
			zombie:Destroy()
		end
	end)
end

return module

What do I do?

#2

Your function is already assuming that there’s already a HumanoidRootPart inside the Zombie, my assumption is the specific part falls after a short while since results in that error a couple seconds later

You should implement a sanity check that there is a HRP before continuing your function:

module.movementcontrol = function(zombie)
	local zomhumroot = zombie:FindFirstChild("HumanoidRootPart")
	if humroot then
	    local zomanoid = zombie.Zombie
	    local anim = zomanoid.Walk
	    local anim2 = zomanoid.Attack
	    local anim3 = zomanoid.Idle
	    local loadanim = zomanoid:LoadAnimation(anim)
	    local loadanim2 = zomanoid:LoadAnimation(anim2)
	    local loadanim3 = zomanoid:LoadAnimation(anim3)
	    local humroot = module.findtarget(zombie)

		zomanoid:MoveTo(humroot.Position, humroot)
		loadanim:Play()
		if (zomhumroot.Position - humroot.Position).magnitude < 5 then
			loadanim2:Play()
			humroot.Parent.Humanoid:TakeDamage(15)
		end
	else
		zomanoid:MoveTo(zomhumroot.Position + Vector3.new(math.random(-50,50),0, math.random(-50,50)), game.Workspace.Ground)
		loadanim:Stop()
		loadanim3:Play()
		wait(3)
		loadanim3:Stop()
		loadanim:Play()
	end
end
#3

Thank you so much! I didn’t add the find first child when I tried this before, but after I did it now works!