Mouse Icon Doesn't Change?

I'm having trouble trying to change the mouse icon in my game. Instead of the default cursor, I want to be able to use a single dot I made into a decal. However, it doesn't work, and nothing pops up/the default Roblox mouse cursor stays active.

local mouse = game.Players.LocalPlayer:GetMouse()
mouse.Icon = "http://www.roblox.com/asset/?id=6578055354"

Clicking on the link will just result in Roblox telling you the page doesn't exist, but it's in my decals list.

List of things I have tried:

Exiting and reopening Roblox Studio
Using "rbxassetid://(number)"

I did try using another decal, and it worked. Although, some of them don't when I try to make them a mouse cursor.

A little side problem I am also having is click detectors. I tried using one of the mouse cursors that did work and hover my mouse over the part with the click detector in it. It didn't work, nor did changing the mouse icon of the click detector in its properties to another decal instead of the default finger pointing cursor.