Default Roblox cursor texture?

[hunterk1241 (AbandonedAccount)]

@MrchipsMa

    local plr = game.Players.LocalPlayer
    local humanoid = plr.Character.Humanoid
    local run = game:GetService("RunService")
    local cam = workspace.CurrentCamera
    local souns = Instance.new("Sound")
    souns.Parent = script
    souns.Name = "Shooted"
    souns.SoundId = "rbxassetid://560908171"
    local relodSound = Instance.new("Sound")
    relodSound.Parent = script
    relodSound.SoundId = "rbxassetid://3606136833"
    relodSound.Name = "reloadsoun"
    local aiming = false
    local aimcf = CFrame.new()

    local gun = game.ReplicatedStorage.Weapons.glockarm:Clone()
    local s = require(game.ReplicatedStorage.WeaponsModules:WaitForChild("Glock18"))

    gun:SetPrimaryPartCFrame(cam.CFrame)

    run.RenderStepped:Connect(function()
    	gun:SetPrimaryPartCFrame(cam.CFrame 
    		*s.weaponpos
    		*aimcf
    	)
    	if aiming then
    		aimcf = aimcf:Lerp(s.AimCFrame, 0.1)
    	else
    		aimcf = aimcf:Lerp(CFrame.new(), 0.1)
    	end
    end)

    gun.Parent = cam

    local idle = gun.Humanoid:LoadAnimation(game.ReplicatedStorage.WeaponsModules.Glock18.Anim.idle)

    idle:Play()

    local shoot = gun.Humanoid:LoadAnimation(game.ReplicatedStorage.WeaponsModules.Glock18.Anim.shoot)
    local Mouse = plr:GetMouse()
    Mouse.Icon ="http://www.roblox.com/asset?id=57571496"
    Mouse.Button1Down:Connect(function()
    	shoot:play()
    	souns:Play()
    	
    Mouse.Button2Down:connect(function()	
    		aiming = true
    	end)
    	
    	Mouse.Button2Up:connect(function()	
    		aiming = false
    	end)
    	
    	game:GetService("UserInputService").InputBegan:Connect(function(input, Game)
    		if Game == true then return end
    		if input.KeyCode == Enum.KeyCode.R then
    			local reload = gun.Humanoid:LoadAnimation(game.ReplicatedStorage.WeaponsModules.Glock18.Anim.reload)
    			reload:Play()
    				relodSound:play()
    		end
    	end)
    end)
    plr.CameraMode = Enum.CameraMode.LockFirstPerson

    local function onDied()
    	gun.Parent.Parent = nil;
    	souns:Remove()
    	relodSound:Remove()
    	plr.CameraMode = Enum.CameraMode.Classic
    	Mouse.Icon =""
    	end


    local function onUpdate(dt)
    	gun:SetPrimaryPartCFrame(cam.CFrame)
    	Mouse.Icon ="http://www.roblox.com/asset?id=57571496"
    end

    humanoid.Died:Connect(onDied);

    run.RenderStepped:connect(onUpdate)
    gun:SetPrimaryPartCFrame(cam.CFrame*s.weaponpos)

I can see that you accidentally wrote the asset ID incorrectly. You forgot about the “/” after asset in “http://www.roblox.com/asset/?=”

What I do suggest is replacing the old asset format with the new one here:

Mouse.Icon = "rbxassetid://[ID]"

It will save you time writing “http://www.roblox.com/asset/?=” over and over for the future