Object reference not set to an instance of an object.
   at DungeonCrawler.UIHelper.UpdateButtonGraphics(PlayerInputState playerInput, LocalPlayerControlComponent playerSession, Dictionary`2 elementDict)
   at DungeonCrawler.FullScreenCrawlLobbyOverlay.RefreshLobby()
   at DungeonCrawler.FullscreenOverlayControllerComponent.CloseFullscreen()
   at DungeonCrawler.NetworkControllerComponent.LeaveGame()
   at DungeonCrawler.NetworkControllerComponent.RunMajorOperation(NetworkSessionParameters networkSessionParameters)
   at DungeonCrawler.NetworkControllerComponent.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)