Error The current identity 2 cannot Class security check lacking permission 6, How to fix the error?

I downloaded a code from the internet (Link: https://www.roblox.com/library/35755937/Explorer-GUI)  and I had a problem: in the Return Game Objects script An error occurred:

 17: 11: 15.290 - The current identity (2) cannot Class security check (lacking permission 6)
17: 11: 15.291 - Stack Begin
17: 11: 15.291 - Script 'Players.BrennoMaturino1.PlayerGui.Explorer Script.Explorer.Find [game] .Return Game Objects', Line 21
17: 11: 15.292 - Stack End

Return Game Objects:

local inDex = 1
local tinDex = script.Parent.Parent.Tindex
local _place = game

script.Parent.MouseButton1Click:Connect(function()
    tinDex.Value = 1
    script.Parent.Parent.Oindex.Value = _place
    for i,v in pairs(script.Parent.Parent.Background:GetChildren()) do
        v.Text = ""
        pcall(function()
            v.Children:Remove()
            end)
    end
    for i = tinDex.Value, tinDex.Value + 15 do
        local cBox = script.Parent.Parent.Background:FindFirstChild("Box[" .. tostring(inDex) .. "]")
        if _place:GetChildren()[i] ~= nil then
            local o = Instance.new("ObjectValue")
            o.Value = _place:GetChildren()[i]
            o.Name = "Children"
            o.Parent = cBox
            cBox.Text = _place:GetChildren()[i].Name
            inDex = inDex + 1
        end
    end 
    inDex = 1
end)