My computer freezes when the clip runs out of ammo in my weapon, why?

When you run out of ammo, your script does not yield in any way so it runs as fast as possible which ends up freezing your computer.

All I did was add a wait() inside an else statement on line 79.

--//Variables
local plr = game.Players.LocalPlayer
local tool = script.Parent.Parent
local hole = tool.Hole
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 reloadTime = config.ReloadTime
local isReloading = false
local firing = false
--//Sounds
local reloadSound = tool.Handle.ReloadSound
local fireSound = tool.Handle.FireSound
local equipSound = tool.Handle.EquipSound
local emptySound = tool.Handle.EmptySound

--//Events
tool.Equipped:Connect(function(mouse)
    equipSound:Play()
    tool.Activated:Connect(function()
    firing = true
    repeat
        if not isReloading then
            if firing == true then
            if ammo.Value > 0 then
                if debounce then
                    --//Play sound
                    fireSound:Play()
                    --//Doesn't allow spamming
                    debounce = true
                    --//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("Black")
                        trace.CanCollide = false
                        trace.Anchored = true
                        trace.Transparency = 0.5
                       wait()
                        --//Show Direction
                        local distance = (hole.CFrame.p - position).magnitude
                        trace.Size = Vector3.new(0.2, 0.2, distance)
                        trace.CFrame = CFrame.new(hole.CFrame.p, position) * CFrame.new(0, 0, -distance/2)

                        --//Remove debris
                        game:GetService("Debris"):AddItem(trace, 0.1)
                    end

                    --//Hit Detection
                    if hit then
                        local humanoid =  hit.Parent:FindFirstChild("Zombie")
                        if humanoid then
                            if hit.Name == "Head" then
                                --//Double damage on headshots
                                humanoid:TakeDamage(dmg.Value*2)
                            else
                                --//Normal Damage on body shots
                                humanoid:TakeDamage(dmg.Value)
                            end
                        end
                    end
                    ammo.Value = ammo.Value - 1
                    wait(coolDown.Value)
                    debounce = true
                end
            else
				wait() --//Added a wait so it yields.
                --//Out of ammo
               -- emptySound:Play()
 	 	end
	end        
end
--if ammo == 0 then 
--firing = false
--end
mouse.Button1Up:Connect(function()
    wait()
firing = false
end)

until firing == false
end)
    --//Reload Event
    mouse.Button1Down:Connect(function(click)
        --key:lower()
        --if key == "r" then
            if not isReloading then
                if clips.Value > 0 then
                    if ammo.Value == 0 then
                    isReloading = true
                    reloadSound:Play()
                    wait(reloadTime.Value)
                    ammo.Value = maxAmmo.Value
                    clips.Value = clips.Value - 1
                    isReloading = false
                end
            end
        end
   end)
end)

This should solve your issue of freezing.