IB-provider-crashes-WL-with-FormatException

CODE:
using WealthLab.Backtest;
using System;
using WealthLab.Core;

namespace WealthScript4 
{
    public class MyStrategy : UserStrategyBase
    {
        public override void Initialize(BarHistory bars)
        {
         double d = 123456789.1234;
         WriteToDebugLog(String.Format("{0:C}", d));
        }

        public override void Execute(BarHistory bars, int idx)
        { }
    }
}