What's wrong with my Server Messages Script?

I have a server messages script that seems to not be working properly. I want everybody in the server to see it, even myself.

This is what I have:

game.Players.PlayerAdded:connect(function(player)
    game:GetService("StarterGui"):SetCore("MakeSystemChatMessage", {
        Text = "[Server]"..player.." has joined";
        Color = Color3.new(255/255, 0/255, 0/255);
        Font = Enum.Font.Arial;
        FontSize = Enum.FontSize.Size24;
    })
end)

It has worked before, but ever since the recent ROBLOX update, it hasn't worked. It shows no errors whatsoever. It is a LocalScript under StarterGui.