there is no error in this simple script. it is just not doing anything.
game.Players.PlayerAdded:Connect(function(plr)
plr.PlayerGui.LoadingScreenGui.Loading.Visible = true
end)
new script that works:
game.Players.PlayerAdded:Connect(function(plr)
plr:WaitForChild("PlayerGui"):WaitForChild("LoadingScreenGui"):WaitForChild("Loading").Visible = true
end)

5 comments
if it helps it is a normal script
Where is the script located
read the title, StarterGui
Is it a server script or local script
he did say it's a "normal script"