Resolving an NRE in my code (C#)

Hey.

So I keep getting a random NRE on this function, and I can't seem to figure out for the life of me what the problem is... I'm hoping you guys can because this has bewildered me.

Code:

void UpdateScoreboard()
        {
            scoreboardList.Clear();
            var items = from pair in points
                        orderby pair.Value descending
                        select pair;
            foreach (KeyValuePair<BasePlayer, int> pair in items)
            {
                string playerName = pair.Key.displayName;
                string text = string.Format(playerName + ", " + pair.Value);
                scoreboardList.Add(text);
            }
            string scoreboardListCsv = string.Join("\n", scoreboardList.ToArray());            foreach (BasePlayer playingPlayer in players)
            {
                if (playingPlayer.net.connection != null && !playingPlayer.IsSleeping())
                {
                    var obj4 = new Facepunch.ObjectList?(new Facepunch.ObjectList("Scoreboard"));
                    CommunityEntity.ServerInstance.ClientRPCEx(new Network.SendInfo() { connection = playingPlayer.net.connection }, null, "DestroyUI", obj4);
                    var obj24 = new Facepunch.ObjectList?(new Facepunch.ObjectList(scoreGUI.Replace("{text}", scoreboardListCsv).Replace("{timeremaining}", gametimerint.ToString() + " seconds left")));
                    CommunityEntity.ServerInstance.ClientRPCEx(new Network.SendInfo() { connection = playingPlayer.net.connection }, null, "AddUI", obj24);
                }
            }
        }

Thanks, PsychoTea.

 

The problem is with commenting parts out is the NRE is extremely random, and as it's part of a game mode it's very tedious to test.
Good idea on the playingPlayer.net != null, I'll try that.