:30:attempt to index local 'inputObject' (a nil value)?

I have a problem with the userInputService and I'm not sure how it works so here I am asking. My goal here is to make a building system.

this is the whole script:

local stone = script.Parent.stone.Value
local log = script.Parent.log.Value
local barracks = game.ReplicatedStorage.buildable.barracks
local players = game:GetService("Players")
local player = players.LocalPlayer
local char = player.Character
local mouse = player:GetMouse()

local pos = Instance.new("Part", char)
pos.Name = "pos"
pos.Position = Vector3.new(char:WaitForChild("HumanoidRootPart").Position.X, char:WaitForChild("HumanoidRootPart").Position.Y * -3, char:WaitForChild("HumanoidRootPart").Position.Z)

wait()

local weld = Instance.new("Weld",pos)
weld.Part0 = char:WaitForChild("HumanoidRootPart")
weld.C0 = char:WaitForChild("HumanoidRootPart").CFrame
weld.Part1 = pos
weld.C1 = pos.CFrame
pos.CFrame = char:WaitForChild("HumanoidRootPart").CFrame * CFrame.new(0, 0, 0)

script.Parent.resources.Text = "stones" .. stone .. "logs" .. log

if script.Parent.craft.MouseButton1Click then
    newbarracks = barracks:Clone()
    newbarracks.Parent = workspace
end

function onKeyPress(inputObject, gameProcessedEvent)
    if inputObject.KeyCode == Enum.KeyCode.G then
        newbarracks.anchor.Value = true
    end
    if newbarracks.anchor.Value == false then
        wait(0.1)
        local posy, posx, posz = pos.Position.Y, pos.Position.X, pos.Position.Z
        newbarracks:MoveTo(Vector3.new(posx, posy + 0 , posz))
    end
end

while wait() do
    onKeyPress()
end


if script.Parent.craft.Text.Changed then
    script.Parent.craft.TextWrapped = false
    wait()
    script.Parent.craft.TextWrapped = true
end

any help would appreciated.