Customizable Weaponry 2.0 Scripting Error

[levarchknight]

[ERROR] addons/customizable weaponry 2.0 rev75/lua/weapons/cw_base/sh_bullets.lua:7: table index is nil
1. unknown - addons/customizable weaponry 2.0 rev75/lua/weapons/cw_base/sh_bullets.lua:7
2. include - [C]:-1
3. unknown - addons/customizable weaponry 2.0 rev75/lua/weapons/cw_base/shared.lua:85
[ERROR] addons/customizable weaponry 2.0 rev75/lua/weapons/cw_base/sh_bullets.lua:7: table index is nil
1. unknown - addons/customizable weaponry 2.0 rev75/lua/weapons/cw_base/sh_bullets.lua:7
2. include - [C]:-1
3. unknown - addons/customizable weaponry 2.0 rev75/lua/weapons/cw_base/shared.lua:85
local function scaleRecoilToMagCapacity(wep, mod)
return mod * wep:Clip1() / wep.Primary.ClipSize
end

CustomizableWeaponry.callbacks:addNew("calculateRecoil", "CalculateRecoilCallback", scaleRecoilToMagCapacity)
Gmod version im running: 14.07.13 No addons except this one addon.