how do i fix Argument 1 missing or nil?

I am new to making UI in Roblox studio and I am trying to make a ring from sonic. what is supposed to happen is that when you touch the ring it will fire a remote event that it will fire a remote event that will update the text label however when i touch the ring the " Argument 1 missing or nil" error message appears.

This is my script which is a child on the ring:

local ring = script.Parent
local ringSparkle = ring.ParticleEmitter
	  ringSparkle.Enabled = false
local ReplicatedStorage = game:GetService("ReplicatedStorage")
local ringUpdate = ReplicatedStorage:WaitForChild("ringCountUpdate")
function destroy(otherPart)
	local partParent = otherPart.Parent
	local humanoid = partParent:FindFirstChild("Humanoid")
	if humanoid then
		ring.Transparency = 1
		ring.CanCollide = false
		ringSparkle.Enabled = true
		wait(1)
		ring:Destroy()
		ringUpdate:FireClient()
	end
end

ring.Touched:Connect(destroy)

and this is my text label local script

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local ringUpdate = ReplicatedStorage:WaitForChild("ringCountUpdate")


local ringCount = script.Parent
local ringCountInt = 0
ringCount.Text = tostring(ringCountInt)

local function addRing ()
	ringCountInt += 1
	ringCount.Text = tostring(ringCountInt)
end

ringUpdate.OnClientEvent:Connect(addRing)