Help on the killfeed system error? [closed]

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