Workspace.Rifle Dummy.Script:46: attempt to index nil with 'Health'?

Hello, I need help on a Dummy NPC I'm trying to make. If there's no target in sight or the target went out of range, it would break and create a error saying: attempt to index nil with 'Health'

This was not supposed to happen because of the way I coded it, here is the code (There is only server-side code, no client code.

local Humanoid = script.Parent.Humanoid
local HumanoidRootPartDummy = script.Parent.HumanoidRootPart
local Animator = Humanoid.Animator
local Loads = {
	Fire = Animator:LoadAnimation(script.Parent.Fire),
	Idle = Animator:LoadAnimation(script.Parent.Idle)
}
local dmg = 7
local range = 79

function findTarget() 	
	for i, child in pairs(workspace:GetChildren()) do
		if child:IsA("Model") and child:FindFirstChild("Humanoid") and child:FindFirstChild("HumanoidRootPart") and child ~= script.Parent then
			local HumanoidRootPart = child:FindFirstChild("HumanoidRootPart")
			local HumanoidTarg = child:FindFirstChild("Humanoid")
			local pos = (HumanoidRootPartDummy.Position - HumanoidRootPart.Position).Magnitude
			if pos < range and HumanoidRootPart and HumanoidTarg then
				return HumanoidRootPart, HumanoidTarg
			end
		end
	end	
end

function bulletGeneration(TargetRootPart)
	local Trail = Instance.new("Beam")
	
	local Attachment1 = Instance.new("Attachment")
	local Attachment2 = Instance.new("Attachment")
	
	Attachment1.Parent = HumanoidRootPartDummy
	Attachment2.Parent = TargetRootPart
	Trail.Attachment0 = Attachment1
	Trail.Attachment1 = Attachment2
	Trail.Enabled = true
	Trail.Color = ColorSequence.new{
		ColorSequenceKeypoint.new(0, Color3.new(1, 1, 1)),
		ColorSequenceKeypoint.new(0.5, Color3.new(1, 0.721569, 0.270588)),
		ColorSequenceKeypoint.new(1, Color3.new(1, 0.933333, 0))
	}
	wait(Loads.Fire.Length / 12)
	Trail:Destroy()
end

while wait() do
	local root, targhum = findTarget()
	if targhum.Health ~= 0 and root and targhum then
		Loads.Fire:Play()
		targhum:TakeDamage(dmg)
		script.Parent.HumanoidRootPart.CFrame = CFrame.lookAt(script.Parent.HumanoidRootPart.Position, root.Position)
		wait(Loads.Fire.Length)
	else
		Loads.Fire:Stop()
		Loads.Idle:Play()
		Loads.Idle.DidLoop:Wait()
	end
end

If you read this all, good job!

I tried almost everything I could, I always miss something that I somehow didn't notice so simple. But I really can't figure this one out.

Also, the BulletGeneration function isn't doing anything visual.

I stopped scripting for like 1 in a half months, so I'm a little rusty.