The thread below include a post which might you if you are having problems with your Indicators when using them within a strategy and you are overloading the Indicator parameters using BarsIndex[] barseries.
The issue has to do with non-primary barseries not getting a Chart object. So if your indicator is used as per above, (overloaded with a non-primary bar object. Example: you want to use an SMA(BarsIndex[1], 20), where BarsIndex[1] is based on a 5m timeframe and your primary timeframe is 1 minute.
