i've added a script with the following code:
--[[ Disable Core Gui ]]--
local StarterGui = game:GetService('StarterGui')
StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.All, false)
But when I play on a server the core gui stay there. Does any one know if this is a bug?

9 comments
So the backpack, chat, and player list don’t go away? Also is this a server script or a local script?
No. they dont, and this is a server script.
Change it to a local script then, that should fix it. Server scripts don’t work on StarterGuis. :P
Stil not working...
This should work in a LocalScript in StarterPlayerScripts. If not, then I'm not sure why, because that should work.
Put the LocalScript in StarterPlayerScripts, StarterCharacterScripts, ReplicatedFirst, StarterGui, or StarterPack.
Probably because some Gui's are just not allowed to get disabled?
Listen to Goulstem. I forgot to tell you localscripts can only work under certain places, as it says in the wiki page. -> http://wiki.roblox.com/index.php?title=API:Class/LocalScript
Thanks guys!