vgui.Create error (Returning nil value)

[Nicksf13]

Hello guys. I was creating a menu for my server, but everytime that I call the DFrame that I created with vgui.Create("DFrame") I'm receiving:
[ERROR] addons/staticmanager/lua/manager/cl_menu.lua:4: attempt to index local 'FMenus' (a nil value)
1. unknown - addons/staticmanager/lua/manager/cl_menu.lua:4
2. include - [C]:-1
3. unknown - addons/staticmanager/lua/autorun/cl_init.lua:2

Here's my code:

local FMenus = vgui.Create("DFrame")
local PSMenus = vgui.Create("DPropertySheet", FMenus)

FMenus:SetSize(600, 400) -- Here's where my code gets wrong
FMenus:Center()
FMenus:ShowCloseButton(true)
FMenus:SetDraggable(false)
	
PSMenus:Dock(FILL)
PSMenus.Paginas = {}
FMenus:MakePopup()

function FMenus:Paint()
end

I don't know why I'm receiving this, because everytime I created a DFrame I made by this way.

[iJohnny]

Maybe you're running this code server-side?
[b]unknown - addons/staticmanager/lua/autorun/cl_init.lua:2[/b] this is shared files location

EDIT: why dumb?

[sannys]

[QUOTE=iJohnny;51543587]Maybe you're running this code server-side?
[b]unknown - addons/staticmanager/lua/autorun/cl_init.lua:2[/b] this is shared files location

EDIT: why dumb?[/QUOTE]

vgui would be nil, and the error would be on the first line for attempting to index it.

[NeatNit]

Your code is probably running too early. Try putting it in InitPostEntity or something.

[Nicksf13]

[QUOTE=NeatNit;51546109]Your code is probably running too early. Try putting it in InitPostEntity or something.[/QUOTE]

Thanks man, problem solved!