Solved Error when sending a message

hello this works fine but the last update destroys it.

here is my code.

Code:

void OnPlayerChat(ConsoleSystem.Arg arg)
        {
            var message = arg.GetString(0);
            if (message.Contains("!players"))
            {
                var playerCount = BasePlayer.activePlayerList.Count;
                if (playerCount > 1)
                    rust.BroadcastChat($"There are currently {playerCount} players online.");
                else
                    rust.BroadcastChat("There is currently 1 player online.");               
            }
        }

ERROR says

Code:

Failed to call hook 'OnPlayerChat' on plugin 'PlayerCount v1.0.3' (NullReferenceException: Object reference not set to an instance of an object)...........

hope someone can help.
thanks