Problems with custom loading bar?

I'm trying to create my own custom loading screen instead of roblox's original. But i'm having trouble with it since i'm a beginner at lua. Code below:

script.Parent:RemoveDefaultLoadingScreen()

local screen = Instance.new("ScreenGui")
screen.Parent = game.Players.LocalPlayer:WaitForChild("PlayerGui")

local frame = Instance.new("Frame")
frame.Parent = screen
frame.BackgroundColor = "Lime green"
frame.Size = UDim2.new(0,800,0,800)

local textLabel = Instance.new("TextLabel")
textLabel.Parent = frame
textLabel.BackgroundTransparency = 1
textLabel.Position = UDim2.new(0,500,0,150)
textLabel.FontSize = Enum.FontSize.Size14

local count = 0
while game.ContentProvider.RequestQueueSize > 0  do
    textLabel.Text = "Loading " .. string.rep(".",count)
    count = (count + 1) % 4
    wait(.3) 
end

screen.Parent = nil

Its okay if its hard to answer, I can use the original one too.

PS: I got this script from the wiki, i just changed it up a bit.