How can I fix this error in my map voting system?

So this is a script from SpooksHD's video of a map voting system and I have rewritten the script several times with help of the video but the error seems to not fix. The error it gives me is: ServerScriptService.Server:103: attempt to concatenate local 'mName' (a nil value) And if you want to check if I have written everything correct here is the link to spooksHD's video: [https://www.youtube.com/watch?v=1eUCfvC7F1A]. Please do try to find a solution quickly because I have nothing to do but work on my game and I can't go on without a fix for this. Here is the part of the script I think the problem is in:

local start = tick()
		while wait() do
			if tick()-start >= settings.mapVoteTime then break end
			local secondsLeft = math.floor(settings.mapVoteTime-(tick()-start))
			stats.Status.Value = secondsLeft.." "..((secondsLeft==1 and "Second")or "Seconds").." Left To Vote!"
			for a,b in pairs(Game.Special.VotingPads:GetChildren()) do
				local playersVoting, mName
				for d,c in pairs(mapVotes) do
					if c.id == tonumber(b.Name:match("%d+")) then
						playersVoting=#c.players
						mName=c.mapName
						break
					end
				end
				b.sGui.Title.Text = mName.." - "..playersVoting.." "..((playersVoting==1 and "Voter") or  "Voters")
			end
		end

Here is the full script:

--Assets--
local rep = game.ReplicatedStorage
local assets = rep.Assets

--Maps--
local maps = assets.Maps

--Signals--
local signals = assets.Signals
local event = signals.Event
local fevent = signals.FEvent

--Static Variables--
local mapVotes = {}

--Game Variables--
local Game = workspace.Game
local stats = Game.Stats
local settings = {
	mapVoteTime=15;
	mapVoteDelay=3;
	playersRequired=1;
} 

--Primary Events--

--[[
	ARRAY = mapVotes
		MapArray
			Id
			mapName
			players
				player=userId
--]]

event.OnServerEvent:connect(function(player, variables)
	if variables.reason == "voteOnMap" then
		--First check if a player already voted on a map, if so change vote.
		for a,b in pairs(mapVotes) do
			for d,c in pairs(b.players) do
				if c.player == player.UserId then
					table.remove(b.players, d)
					break
				end
			end
		end
		--Add player to mapVotes
		for a,b in pairs(mapVotes) do
			if b.id == variables.ItemNum then
				table.insert(b.players, {player=player.UserId})
			end
		end
	elseif variables.reason == "removeFromVote" then
				for a,b in pairs(mapVotes) do
			for d,c in pairs(b.players) do
				if c.player == player.UserId then
					table.remove(b.players, d)
					break
				end
			end
		end
	end
end)

function getMap()
	local randomMap = maps:GetChildren()[math.random(1,#maps:GetChildren())]
	for a,b in pairs(mapVotes) do
		if b.mapName == randomMap.Name then
			return getMap()
		end
	end
end

while wait() do
	if #game.Players:GetPlayers() < settings.playersRequired then 
		local playersNeeded = settings.playersRequired-#game.Players:GetPlayers()
		stats.Status.Value = playersNeeded.." "..((playersNeeded==1 and "Player")or "Players").." needed to play!"
	else
		--Assign maps
		mapVotes={}
		for a,b in pairs(Game.Special.VotingPads:GetChildren()) do
			table.insert(mapVotes, {id=tonumber(b.Name:match("%d+")); mapName=getMap(); players={};})
		end
		
		--Fire Clients, start sending in votes.
		event:FireAllClients({reason="StartVoting"})
		
		--Do main loop
		local start = tick()
		while wait() do
			if tick()-start >= settings.mapVoteTime then break end
			local secondsLeft = math.floor(settings.mapVoteTime-(tick()-start))
			stats.Status.Value = secondsLeft.." "..((secondsLeft==1 and "Second")or "Seconds").." Left To Vote!"
			for a,b in pairs(Game.Special.VotingPads:GetChildren()) do
				local playersVoting, mName
				for d,c in pairs(mapVotes) do
					if c.id == tonumber(b.Name:match("%d+")) then
						playersVoting=#c.players
						mName=c.mapName
						break
					end
				end
				b.sGui.Title.Text = mName.." - "..playersVoting.." "..((playersVoting==1 and "Voter") or  "Voters")
			end
		end
		
		--Get winner
		table.sort(mapVotes, function(a,b) return #a.players>#b.players end)
		
		for a,b in pairs(Game.Special.VotingPads:GetChildren()) do
			if tonumber(b.Name:match("%d+")) == mapVotes[1].id then
				b.sGui.Title.Text = "Winner!"
				stats.Status.Value = mapVotes[1].mapName.." was chosen!"
			else
				b.sGui.Title.Text = "Lost Vote!"
			end
		end
		
		wait(settings.mapVoteDelay) 
	end	
end