How is this a 'nil value'? I put 'if' so it should ignore it if it's nil

I'm getting an error saying 'attempt to index a nil value' Something is wrong with this bit of code, but I have no idea what;

for i,v in pairs(plrs:GetChildren()) do
	if v.Character and v.Character.HumanoidRootPart then v.Character.HumanoidRootPart.CFrame = CFrame.new(Vector3.new(-169.21, 5.044, 11.959))
	end
end

It happens when the character has fallen down into the emptiness (the FallenPartsDestroyHeight).

for i, v in pairs(game.Players:GetChildren()) do 
	if v:IsA("Player") and v.Character then 
		local character = v.Character
		if character.Humanoid then 
			if character.Humanoid.Health > 0 then 
			--code
			end
		elseif not character.Humanoid or character then 
			print("character is nil")
		end
	end
end

Try using FindFirstChild() instead.

Also, use Players:GetPlayers(), not Players:GetChildren()

You can do it like this:

for i,v in pairs(plrs:GetPlayers()) do
	if v.Character and v.Character:FindFirstChild("HumanoidRootPart") then
		v.Character.HumanoidRootPart.CFrame = CFrame.new(Vector3.new(-169.21, 5.044, 11.959))
	end
end

Or like this:

for i,v in pairs(plrs:GetPlayers()) do
	local hrp = v.Character and v.Character:FindFirstChild("HumanoidRootPart")
	if hrp then
		hrp.CFrame = CFrame.new(Vector3.new(-169.21, 5.044, 11.959))
	end
end