Items not equipping in custom inventory system?

Im trying to make an inventory system, a drag inventory system, yet i found something strange. It works perfectly in Studio, yet when i hop onto Roblox, the items dont' equip. Why? I don't know.

This is the "Flawed Script"

--//Services
local Players = game:GetService("Players")
local UIS = game:GetService("UserInputService")
local RS = game:GetService("ReplicatedStorage")

--//Events
local UpdateAncestory = RS:WaitForChild('UpdateAncestory')

--//Objects
local Slots = { script.Parent:WaitForChild('One'), 
                script.Parent:WaitForChild('Two'),
                script.Parent:WaitForChild('Three'),
                script.Parent:WaitForChild('Four'),
                script.Parent:WaitForChild('Five'),
                script.Parent:WaitForChild('Six'),
                script.Parent:WaitForChild('Seven'),
                script.Parent:WaitForChild('Eight')}

--//PlayerObjects
--in code...

local Backpack = Players.LocalPlayer:WaitForChild('Backpack', math.huge)

--//Functions
function Dequip(Char)
    for i, v in ipairs(Slots) do
        v.Equipped.Value = false
        v.BackgroundColor3 = Color3.fromRGB(0,0,0)
        if Char:FindFirstChildOfClass('Tool') then
            Char:FindFirstChildOfClass('Tool'):Destroy()
        end
    end
end

--//Code
UIS.InputBegan:connect(function(input)
    local Char = Players.LocalPlayer.Character
    local Humanoid = Char:WaitForChild('Humanoid')

    if script.Parent:FindFirstChild(input.KeyCode.Name) then
        local SlotEquip = script.Parent[input.KeyCode.Name]
        if SlotEquip.Equipped.Value == false and SlotEquip.Tool.Value ~= nil then
            Dequip(Char)
            SlotEquip.Equipped.Value = true
            SlotEquip.BackgroundColor3 = Color3.fromRGB(255, 255, 0)
            if SlotEquip.Tool.Value ~= nil then Humanoid:EquipTool(SlotEquip.Tool.Value:Clone()) end
        elseif SlotEquip.Equipped.Value == true and SlotEquip.Tool.Value ~= nil then
            Dequip(Char)
        end
    end
end)