Crashed in Symbol.Tick event with InvalidOperationException: Sequence contains no elements

[teymourian]

Hi dear
my code is

_renkoBars = new RenkoBars(RankoSizeInPips, Symbol, this);
private void RenkoBars_OnBar(object sender, OhlcBar newBar, OhlcBar oldBar)
{            
  Print(_renkoBars.LastBar.Close);
}   

after run error
30/09/2022 15:55:22.730 | Crashed in Symbol.Tick event with InvalidOperationException: Sequence contains no elements
30/09/2022 15:55:22.871 | CBot instance [RenkoBot, EURUSD, m1] crashed with error "Crashed in Symbol.Tick event with InvalidOperationException: Sequence contains no elements"

error for [Print(_renkoBars.LastBar.Close);]

pls help
tnk