Help on the killfeed system error?

So, basically every time I test this kill-feed script the output throws me this: https://ibb.co/nAgsW8 I checked the script and there are no errors.

how can I fix it?

Here's the code: (sorry, it's a lot)

Victim = "" -- The person who died
Killer = "" -- The person who killed the victim
kf = nil -- The gui

function update() -- Updates the System
	player = game.Players:GetChildren() -- Requires players in server
	
	for i = 1, #player do -- repeats until all players. then returns
		kf = player[i].PlayerGui.KillFeed -- Sets "up" as the killfeed in the player gui
		kf1 = kf.kf1
		kf2 = kf.kf2
		kf3 = kf.kf3
		kf4 = kf.kf4
		kf5 = kf.kf5
		kf1.Text = kf2.Text
		kf2.Text = kf3.Text
		kf3.Text = kf4.Text
		kf4.Text = kf5.Text
		kf5.Text = "" ..Killer.. " killed: " ..Victim.. ""
	end
	
	kf = game.StarterGui.Update
	kf1 = kf.kf1
	kf2 = kf.kf2
	kf3 = kf.kf3
	kf4 = kf.kf4
	kf5 = kf.kf5
	kf1.Text = kf2.Text
	kf2.Text = kf3.Text
	kf3.Text = kf4.Text
	kf4.Text = kf5.Text
	kf5.Text = "" ..Killer.. " killed: " ..Victim.. ""
end

function onPlayerEntered(newPlayer)
	-- Stats data
	
	-- Script
	while true do
		if newPlayer.Character ~= nil then break end 
		wait(5)
	end
	
	local Humanoid = newPlayer.Character.Humanoid -- Get Humanoid
	Humanoid.Died:connect(function()
		onHumanoidDied(humanoid, newPlayer) -- Executes on humanoid died (main script)
	end)
	
	newPlayer.Changed:connect(function(property)
		 onPlayerRespawn(property, newPlayer) -- Executes respawn function
	end)
	
	
end
	
function Send_Death_Event(victim, killer)
	local KillerName = game.Players.LocalPlayer
	-- Sets the killer to the player because the killed themself
	if killer ~= nil then KillerName = KillerName.Name end
	print("Death event: ", victim.Name, " KILLED by ", KillerName)
	Victim = victim.Name -- Set's the victim
	Killer = KillerName -- Set's the killer
	
	update() -- Updates the system
	
	if shared["deaths"] ~= nil then
		shared["deaths"](victim, killer)
		print("SENT DB DEATH EVENT") -- Sends the event
	end
end

function Send_DB_Event_Kill(killer, victim) 
	print("KILL EVENT. ", killer.Name, " BLOXXED ", victim.Name)
	
	if shared["kills"] ~= nil then
		shared["kills"](killer, victim)
		print("SENT DB KILL EVENT")
	end 
end

function onHumanoidDied(humanoid, player)
	-- remove spree in stat
	-- -1 score
	
	local killer = getKillerOfHumanoidIfStillInGame(humanoid) -- Get the killer in game
	Send_Death_Event(player, killer) -- Sends death event
	handleKillCount(humanoid, player) -- Handles the kill count
end
	
function onPlayerRespawn(property, player)
	if property == "Character" and player.Character ~= nil then
		local humanoid = player.Character.Humanoid -- Get Humanoid
		local p = player -- Player
		local h = humanoid -- Find the humanoid
		
		humanoid.Died:connect(function()
			 onHumanoidDied(h, p) -- Runs the event
		end) 
	end
end
	
function getKillerOfHumanoidIfStillInGame(humanoid) 
	local tag = humanoid:findFirstChild("creator") -- Finds the creator
	
	if tag ~= nil then 
		local killer = tag.Value 
		
			if killer.Parent ~= nil then
				return killer 
		end
	end	
	return nil
end

function handleKillCount(humanoid, player) 
	local killer = getKillerOfHumanoidIfStillInGame(humanoid)
	
	if killer ~= nil then
		local stats = killer:findFirstChild("leaderstats") 
		if stats ~= nil then
			-- Sets the score up by 2
			-- Sets the spree up by 1
		else
			-- Sets the score down by 1
			-- Sets the spree to 0
		end
		Send_DB_Event_Kill(killer, player) 
	end
end
	
game.Players.ChildAdded:connect(onPlayerEntered) -- OnPlayer enter