RemoteFunction being a noob, help?

I keep getting this error and it's annoying as all hell

Players.Player.Backpack.BoardButtons(ignore):49: bad argument #2 to '?' (string expected, got nil)

*Server script: *

wait(script.Parent.Events.Senders.LocalTimeLength:InvokeClient(game.Players:GetPlayers()[math.random(1,#game.Players:GetPlayers())], name, k))

*Local Script: *

events.Senders.LocalTimeLength.OnClientInvoke = function(plr, name,k)
    return board["Main(EDIT)"][name][k].TimeLength
end