How to fix the error: "Attempt to index a nil value"? Help please.

m = Instance.new("Message")
h = Instance.new("Hint")
m.Parent = game.Workspace
h.Parent = game.Workspace
while true do
    if game.Players.NumPlayers == 1 then
        m.Text = "Loading-Please wait."
        wait(3)
        Spawns = game.Workspace.Elevator.ElevatorSpawn:GetChildren()
        Spawnz = game.Workspace.LobbySpawn:GetChildren()
        m.Text = "Teleporting to Elevator"
        wait(1)
        for i, v in pairs(game.Players:GetPlayers()) do
            name = v.Name
            check = game.Workspace:FindFirstChild(name)
            if check then
                checkHumanoid = check:FindFirstChild("Humanoid")
                if checkHumanoid then
                    check:MoveTo(Spawns[1].Position)
                end
            end
        end
    end
    wait(3)
end

Whenever I run this script the output states: attempt to index field '?' (a nil value). The line it is having the error is the line that says: check:MoveTo(Spawns[1].Position). It doesn't seem to be recognizing "Spawns" as a variable. In the variables of Spawns and Spawnz the ElevatorSpawn and LobbySpawn are both models, each containing 10 parts inside of them.