EventDataPoint-could-not-be-found

CODE:

using WealthLab.Backtest;
using WealthLab.Core;
using WealthLab.Data;
using System.Drawing;

namespace WealthScript2 
{
   public class MyStrategy1 : UserStrategyBase
   {
      //create indicators and other objects here, this is executed prior to the main trading loop
      public override void Initialize(BarHistory bars)
      {
         if (bars.EventDataPoints.Count > 0)
         {
            EventDataPoint fdp = bars.EventDataPoints[bars.EventDataPoints.Count - 1];
            DrawHeaderText("The most recent event item is a " + fdp.ItemName + " reported on " + fdp.Date.ToShortDateString(), WLColor.Black, 18);
         }
      }

      //execute the strategy rules here, this is executed once for each bar in the backtest history
      public override void Execute(BarHistory bars, int idx)
      {
      }
   }
}