Workspace.GoKart.REV_FE_Sounds.Handler:44: attempt to call field '?' (a nil value) WHY?

local car = script.Parent.Parent
local Sounds = {}
local F = {}

F.newSound = function(name,par,id,pitch,loop)
	for i,v in pairs(Sounds) do
		if i==name then
			v:Stop()
			v:Destroy()
		end
	end
	
	local sn = Instance.new("Sound",par)
	
	sn.Name = name
	sn.SoundId = id
	sn.Pitch = pitch
	sn.Looped = loop
	sn.AncestryChanged:connect(function(child,parent) print(parent) end)
	Sounds[name]=sn
end

F.updateSound = function(sound,id,pit,vol)
	local sn = Sounds[sound]
	if id~=sn.SoundId then sn.SoundId = id end
	if pit~=sn.Pitch then sn.Pitch = pit end
end

F.pauseSound = function(sound)
	Sounds[sound]:Pause()
end

F.stopSound = function(sound)
	Sounds[sound]:Stop()
end

F.removeSound = function(sound)
	Sounds[sound]:Stop()
	Sounds[sound]:Destroy()
	Sounds[sound]=nil
end

script.Parent.OnServerEvent:connect(function(pl,Fnc,...)
	F[Fnc](...)
end)

wait(0.1)

car.DriveSeat.ChildRemoved:connect(function(child)
	if child.Name=="SeatWeld" then
		F.removeSound("Rev")
	end
end)

My other scripts are set out like this too but they work, but this does not ;/