Trying to make a door break script but an error shows up and the obj value dosen't change?

I am trying to make a script where you can break doors and walls for a game. But when I click on it there displays an error.

Error: "11:30:47.281 - Players.iiLevelMaker.PlayerGui.ScreenGui.Frame.HealthBG.Bar.LocalScript:10: attempt to index field 'Value' (a nil value)"

Serverscript (Inside Part):

script.Parent.ClickDetector.MouseClick:connect(function(player)
    local obj = script.Parent

    game:GetService("ReplicatedStorage").cutWood:FireClient(player, obj)
end)

LocalScript (Inside the "Bar" object seen in the error) 1st:

local player = game.Players.LocalPlayer
local obj = script.Parent.Obj

script.Parent.Health.Changed:connect(function(player)
    local prog = script.Parent.Health

    script.Parent:TweenSize(UDim2.new(prog.Value/100, 0, 1, 0), "In", "Linear", .1)
    if prog.Value <= 0 then
        prog.Value = 0
        obj.Value.Anchored = false
    end
end)

2nd Local script:

game:GetService("ReplicatedStorage").cutWood.OnClientEvent:connect(function(player, obj)
    script.Parent.Obj.Value = obj
    script.Parent.Health.Value = script.Parent.Health.Value - 10
end)

The health works fine, but the "Obj" value wont change, it's a objectvalue. It's supposed to change to the part the player is hitting.