Exception-accessing-NamedSeries-by-index

Cannot access NamedSeries TimeSeries from barHistory
Initialize Exception (CallPut_TSLA.12.23.2021) Line 49 - Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')
at WealthLab.Core.DateSynchedList`1.get_Item(Int32 idx)
at WealthScript2.MyStrategy.Initialize(BarHistory putCallbars) in :line 49
at WealthLab.Backtest.UserStrategyExecutor.NewAlgo(List`1 symbols)

CODE:


BarHistory barPCr = GetHistory(bar, "PCR_" + bar.Symbol.Split('_')[1]);
      foreach (var ns in barPCr.NamedSeries)
         {
            WriteToDebugLog("KEY: " + ns.Key);            
            TimeSeries TS = ns.Value;
            WriteToDebugLog("COUNT: " + TS.Count);

            Double a = TS[2];
            TimeSeries tt = TS.Clone();
               
            PlotTimeSeries(tt, ns.Key, "PCR", _baseColor, _line);
         }