How to fix the "attempt to get length of a userdata value" problem on math.random ?

So, I'm making a game where there has to be a chosen map but when I try to use math.random on it, it gives me an error:

attempt to get length of a userdata value

Here's the script I used:

local Maps = game.ServerStorage.Maps

while true do
	local chosenMap = Maps[math.random(1, #Maps)]
	print(chosenMap.Name)
end

This is getting very annoying. Am I doing something wrong?