not referencing

Hi @all,

I have no more idea why the reference of an custom indikator will not be found.This is an excerpt of an Testindicator referencing an HeikinAshi, which is selected... Please look at both, source and dialog setting:

using System;
using cAlgo.API;
using cAlgo.API.Internals;
using cAlgo.API.Indicators;

namespace cAlgo
{
    [Indicator(IsOverlay = false, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class TestIndi : Indicator
    {
        [Parameter(DefaultValue = 1)]
        public TimeFrame SeriesType { get; set; }

        [Output("Main")]
        public IndicatorDataSeries Result { get; set; }

        private MarketSeries _series;
        private HeikinAshi _indi;

        protected override void Initialize()
        {
            _series = MarketData.GetSeries(SeriesType);
            _indi = Indicators.GetIndicator<HeikinAshi>();
        }

        public override void Calculate(int index)
        {
            if (_series.Open[index - 1] >= _series.Close[index - 1])
            {
                Result[index] = -1;
            }
            else
            {
                Result[index] = 1;
            }
        }
    }
}