--//Local Script Inside folder
--//Variables
local plr = game.Players.LocalPlayer
local tool = script.Parent
local hole = tool.Bullet
local handle = tool.Handle
local debounce = true
local config = tool.Config
local range = config.Range
local dmg = config.Damage
local coolDown = config.CoolDown
local clips = config.Clips
local ammo = config.Ammo
local maxAmmo = config.MaxAmmo
local allowTracing = config.AllowTracing
local mousea = plr:GetMouse()
local mb1down = false
local flash = script.Parent.flash
local da = flash.da
local db = flash.db

--//Events
tool.Equipped:connect(function(mouse)
	allowTracing.Value = true
	mousea.Button1Down:connect(function()
		if mb1down == false then
		local mb1down = true
		while mb1down == true do
		wait()
		if debounce == true then
			--//something..
			mouse.Button1Up:connect(function()
				mb1down = false
			end)
			--//Doesn't allow spamming
			debounce = false
			--//Ray Get, Set
			local ray = Ray.new(hole.CFrame.p, (mouse.Hit.p - hole.CFrame.p) * range.Value)
			local hit, position = workspace:FindPartOnRay(ray, plr.Character, false, true)
			
			--//Bullet Tracing
			if allowTracing.Value == true then
				--//Make part
				local trace = Instance.new("Part", workspace)
				trace.Material = Enum.Material.Neon
				trace.BrickColor = BrickColor.new("New Yeller")
				trace.CanCollide = false
				trace.Anchored = true
				trace.Transparency = 0.7
				da.Transparency = 0
				db.Transparency = 0		
				flash.flash.Enabled = true
				script.Parent.Sound:Play()
				
				--//Show Direction
				local distance = (hole.CFrame.p - position).magnitude
				trace.Size = Vector3.new(0.05, 0.05, 0.7)
				local it = math.random()*0.5
				local n = math.random(0,1)
				if n==0 then it=it*-1 end
				trace.CFrame = CFrame.new(hole.CFrame.p, position) * CFrame.new(it, 0, -distance/2)
				
				--//Remove debris
				game:GetService("Debris"):AddItem(trace, 0.1)
				--//Hit Detection

				if hit then
					local humanoid =  hit.Parent:FindFirstChild("Humanoid")
					if humanoid then
						if hit.Name == "Head" then
							--//Double damage on headshots
							humanoid:TakeDamage(dmg.Value*1.5)
						else
							--//Normal Damage on body shots
							humanoid:TakeDamage(dmg.Value)
						end
					end
				end
			end
			wait(coolDown.Value)
			da.Transparency = 1
			db.Transparency = 1
			flash.flash.Enabled = false
			script.Parent.Sound:Pause()
			debounce = true
		end
		end
		end
	end)
end)

tool.Unequipped:connect(function()
	allowTracing.Value = true
end)

So when I equip the tool then unequip it then equip it again and then try to shoot it, it sais: This Mouse is no longer active. (Line 38)