[SOLVED] How come my custom Tool Equipping system keeps sending the same error?

For the past 5 hours I've been working on a Tool Equipping system, but for some reason I keep being sent the exact same Error. I think I've located the the source to the issue, but when ever I attempt to fix it never works.

The script is located in the StaterPlayerScripts.
The script only starts when an event called "SpawnEvent"

--Error

is not a valid member of Backpack "Backpack" - Client - LocalScript:66

local Players = game:GetService("Players")
local StarterGui = game:GetService("StarterGui")
local UserInputService = game:GetService("UserInputService")
local ReplicatedStorage = game:GetService("ReplicatedStorage")

local Player = Players.LocalPlayer

local Events = ReplicatedStorage:WaitForChild("Events")

local SpawnEvent = Events:WaitForChild("SpawnEvent")

local PlrBackPack = Player:WaitForChild("Backpack")

local Weapons = {

	Primary = "",

	Secondary = "",

	Melee = ""

}

local HasPrimary = false
local HasSecondary = false
local HasMelee = false

--------------------Tool Equipping 
local function SetUp()
	print(PlrBackPack:GetChildren())
	
	for i, Tool in pairs(PlrBackPack:GetChildren()) do --Empty even though it shows and I know it isn't empty.
		if Tool:isA("Tool") then
			if Tool:GetAttribute("WeaponType") == "Primary" then
				Weapons.Primary = Tool.Name
				print(Weapons.Primary.Name)
			elseif Tool:GetAttribute("WeaponType") == "Secondary" then
				Weapons.Secondary = Tool.Name
				print(Weapons.Secondary.Name)
			elseif Tool:GetAttribute("WeaponType") == "Melee" then
				Weapons.Melee = Tool.Name
				print(Weapons.Melee.Name)
			end
		end
	end
	
end

local function OnInput(input, Chat)	
	local Character = Player.Character
	local Humanoid = Character.Humanoid
	
	if Chat then return end

	local GetKeyCode = input.KeyCode
	if GetKeyCode == Enum.KeyCode.One then
		if HasPrimary == false then
			Humanoid:EquipTool(PlrBackPack[Weapons.Primary])
			HasPrimary = true
			HasSecondary = false
			HasMelee = false
		end
	elseif GetKeyCode == Enum.KeyCode.Two then
		if HasSecondary == false then
			Humanoid:EquipTool(PlrBackPack[Weapons.Secondary])
			HasPrimary = false
			HasSecondary= true
			HasMelee = false
		end
	elseif GetKeyCode == Enum.KeyCode.Three then
		if HasMelee == false then
			Humanoid:EquipTool(PlrBackPack[Weapons.Melee])
			HasPrimary = false
			HasSecondary = false
			HasMelee = true
		end
	end

end

UserInputService.InputBegan:Connect(OnInput)

SpawnEvent.OnClientEvent:Connect(function()
	SetUp()
	
	wait(.1)
	
	OnInput({KeyCode = Enum.KeyCode.One})-- initializes the force tool equipping
end)