[solved] attempt to index nil with 'lower'?

This code is supposed to destroy any object that is in a table, but, for some reason I get the error attempt to index nil with 'lower'attempt to index nil with 'lower'

local banned = {"baseplate"}

local dec = game:GetDescendants()

while true do
	wait()
	for _,v in ipairs(banned) do
		for _,a in ipairs(dec) do
			wait()
			if a.Name:lower().find(v.Name:lower()) then
				a:Destroy()
			end
		end
	end
end

Anyone know why this happens? Thanks.