Tycoon dropper wont drop but other droppers will?

wait(2)
workspace:WaitForChild("PartStorage")

while true do
    wait(1.5) -- How long in between drops
    local part = Instance.new("Part",workspace.PartStorage)
    part.BrickColor=script.Parent.Parent.Parent.DropColor.Value
    part.Material=Enum.Material.CorrodedMetal
    local cash = Instance.new("IntValue",part)
    cash.Name = "Cash"
    cash.Value = 5 -- How much the drops are worth
    part.CFrame = script.Parent.Drop.CFrame - Vector3.new(0,1.4,0)
    part.FormFactor = "Custom"
    part.Size=Vector3.new(0.5, 0.5, 0.5) -- Size of the drops
    part.TopSurface = "Smooth"
    part.BottomSurface = "Smooth"
    game.Debris:AddItem(part,20) -- How long until the drops expire
end

If that doesnt show much ^^^^^ i have a Gyazo of it https://gyazo.com/23df0e7fdbabc4cf4c6409471352f3ca

That is my script and for some weird reason it wont drop. The only thing it says with this is 09:38:12.392 - DropColor is not a valid member of Model