The current identity (2) cannot Class security check (lacking permission 1) Error problem roblox?

There's this error that come's up called "20:43:08.965 - The current identity (2) cannot Class security check (lacking permission 1)" How do i fix it.

local KnifeSimulator = Instance.new("ScreenGui")
local frame = Instance.new("Frame")
local open = Instance.new("TextButton")
local main = Instance.new("Frame")
local title = Instance.new("TextLabel")
local credit = Instance.new("TextLabel")
local havmoney = Instance.new("TextButton")
local tpallplayer = Instance.new("TextButton")
local close = Instance.new("TextButton")
--Script And Gui Config
KnifeSimulator.Name = "KnifeSimulator"
KnifeSimulator.Parent = game.CoreGui

its the code at the bottom thanks.