Concatenation Output Error In Server Script?

My script is used for a map voting system consisting of 3 pads on the ground which users stand on to vote. However, on line 104 of this script, I am getting this error: 09:49:22.066 - ServerScriptService.Server:108: attempt to concatenate local 'mName' (a nil value).

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 g_maps = Game.Maps
local settings = {
	mapVoteTime =15;
	mapVoteDelay = 3;
	playersRequired = 1;
	mapTeleportDelay = 2;
}

--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 the 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 = "Chosen!"
				stats.Status.Value = mapVotes[1].mapName.." was chosen"
				b.sGui.Title.BackgroundColor3 = Color3.fromRGB(0,255,0)
			else 
				b.sGui.Title.Text = "Lost Vote!"
			end
		end
		
		--Load  Map
		local map = maps[mapVotes[1].mapName]:Clone()
		map.Parent = g_maps
		
		wait(settings.mapTeleportDelay)
		
		--Teleport Players
		
		local cachedSpawns = {}
		local playersPlaying = {}
		for a,b in ipairs(game.Players:GetPlayers()) do
			local character = b.Character or b.CharacterAdded:wait()
			if character then
				local randomSpawn = map.Spawns:GetChildren()[Random.new():NextInteger(1, #map.Spawns:GetChildren())]
				if cachedSpawns[randomSpawn] then
					repeat randomSpawn = map.Spawns:GetChildren()[Random.new():NextInteger(1, #map.Spawns:GetChildren())] wait() until not cachedSpawns[randomSpawn]
				end
				cachedSpawns[randomSpawn] = true
				character:SetPrimaryPartCFrame(randomSpawn.CFrame * CFrame.new(0,2.25,0))
				table.insert(playersPlaying,b.UserId)
			end
		end
		
		wait(settings.mapVoteDelay)
		
		--Unload Map--
		
		map:Destroy()
		
		--Teleport Players Back--
		for a,b in ipairs(playersPlaying) do
			local player = game.Players:GetPlayerByUserId(b)
			if player then
				local character = player.Character or player.CharacterAdded:wait()
				if character then
					character:SetPrimaryPartCFrame(CFrame.new())
				end
			end
		end
	end
end
`~~~~~~~~~~~~~~~~~

`

It errors because "mName" is a nil value. You could use tostring(mName) to avoid this error, however it would show up as

"nil - x Voters"

You could throw in the line at 108 to line 105 instead and move the "break" part to 106. That should fix your issue.