Object reference not set to an instance of an object.
   at DungeonCrawler.NetworkGameManagerComponent.SpawnPlayersArena()
   at DungeonCrawler.NetworkControllerComponent.networkSession_GameStarted(Object sender, EventArgs e)
   at DungeonCrawler.CustomNetworkSession.StartGame()
   at DungeonCrawler.FullScreenArenaLobbyOverlay.StartCrawlGame()
   at DungeonCrawler.FullScreenArenaLobbyOverlay.startGameMouseButton_MouseLeftClick(Object sender, PlayerIndex player)
   at DungeonCrawler.UIMouseBox.TriggerMouseClick(PlayerIndex player)
   at DungeonCrawler.UIHelper.HandleMousing(List`1 baseElements, Rectangle bounds, Viewport viewPort, PlayerInputState input)
   at DungeonCrawler.FullScreenArenaLobbyOverlay.UpdateLobbyExpanded()
   at DungeonCrawler.FullScreenArenaLobbyOverlay.Update(GameTime gameTime)
   at DungeonCrawler.FullscreenOverlayControllerComponent.Update(GameTime gameTime)
   at Microsoft.Xna.Framework.Game.Update(GameTime gameTime)
   at DungeonCrawler.DungeonCrawlerGame.Update(GameTime gameTime)
   at Microsoft.Xna.Framework.Game.Tick()
   at Microsoft.Xna.Framework.SDL2_FNAPlatform.RunLoop(Game game)
   at Microsoft.Xna.Framework.Game.Run()
   at DungeonCrawler.Program.Main(String[] args)