Table expected, got function

[AnonTakesOver]

Okay, wtf is happening, I cannot find this anywhere, I'm making something for someone, works fine for me, this is the code

hook.Add("PlayerButtonDown", "OpenDermaMenu", function(ply, key)
        faction = faction or {}
	if(key == 97) then
		net.Start("ShowEveryone")
			net.WriteTable(faction)
		net.Send(ply)
		return
	end
	if(key == 98) then
		plyFaction = ply:GetFactions()
		net.Start("FactionManager")
			net.WriteTable(faction)
			net.WriteTable(plyFaction)
		net.Send(ply)
		return
	end
end)
 
 
function meta:GetFactions()
	faction = faction or {}
	local plytable = {}
	for k,v in pairs(faction) do
		for a,b in pairs(faction[k].usersid) do
			if b == self:SteamID() then
				table.insert(plytable, k);
			end
		end
	end
	return plytable;
end

Error:

 [ERROR] lua/includes/modules/net.lua:64: bad argument #1 to 'pairs' (table expected, got function)
1. pairs - [C]:-1
2. WriteTable - lua/includes/modules/net.lua:64
3. fn - addons/darkrpfactions/lua/sv_faction.lua:48
4. unknown - addons/ulib/lua/ulib/shared/hook.lua:183

line 48 = net.WriteTable(faction)

What is going on >.<
Works 100% for me, give it to him, this happens,
He is on Linux, I am on Windows...

[editline]18th April 2014[/editline]

Okay, apparently it works now, maybe he had some addon or something, he fixed it his end.