19: attempt to index a nil value?

I'm trying to make a killstreak system that if your killstreak is 5 or more you get a crown and if it's less than 5 you lose the crown. But the problem is that the RemoveCrown function is giving me an error saying like I said in the title:

19: attempt to index a nil value.

Script:

-- Functions

function AddCrown(Player)
	repeat wait() until Player.Character
	
	local Char = Player.Character
	local Head = Char.Head
	
	local Crown = game.ServerStorage.CrownPart:Clone()
	Crown.Parent = Head
	
	while true do
		wait(0.01)
		Crown.CFrame = CFrame.new(Head.Position + Vector3.new(0, 3, 0))
	end
end

function RemoveCrown(Player)
	Player.Character.Head:FindFirstChild("CrownPart"):Destroy()
end

-- Runs functions

game.Players.PlayerAdded:connect(function(Player)
	repeat wait() until Player.Character
	
	local Killstreak = Player:WaitForChild("PlayerValues").Killstreak
	local Char = Player.Character
	
	while true do
		wait(0.1)
		
		if Killstreak.Value >= 5 then
			AddCrown(Player)
		else
			RemoveCrown(Player)
		end
	end
end)

I would really appreciate it if you help me with my problem, Plus I'll accept your answer.

Thanks, MajinBluee

###Line 19 errors because you didn’t check if the child exists. Yes you used FindFirstChild, but no if statements to check its existence. There are some people who add ~= nil to check the existence of an object, but is redundant and inefficient.

local crown = Player.Character:FindFirstChild"Crown"

if crown then
    crown:Destroy()
end

###I put the crown as an accessory inside of the character model.

Hello! You need to fix RemoveCrown function!

function RemoveCrown(Player)
if Player.Character.Head:FindFirstChild("CrownPart") then
Player.Character.Head:FindFirstChild("CrownPart"):Destroy()
end
end

If it helped you, don't forget to accpet the answer!

Marijus