why do I keep getting No method name passed in __namecall for Object?

local x = 81.6
local y = -10.1
local z = -52
local Map = game.ServerStorage.Maps
local Maps = game.ServerStorage.Maps:GetChildren()

	-- Map selection
local function mapchoice()

    local Choose = Maps[math.random(1,#Maps)]
	Choose.Name = "ChosenMap"
	local placemap = Choose:Clone()	
	placemap:SetPrimaryPartCFrame(CFrame.new (x, y, z))
	placemap.Parent = game.Workspace()

end 

	wait (Resttime)
	mapchoice()

I've been stuck on these lines of code for months.