The first problem people had was related to the fact that my instructions demanded that no accounts were opened. This did not allow the platform to have the accurate currency symbols it needs to download the data. Furthermore, if you open and then close an account and then try to download data the program gives you an error about no data being available for download. After a while of tweaking to find a reproducible way to achieve 90% modeling quality backtesting I have been able to done so and made this small video tutorial, after all, one image says more than a thousand words (imagine a video !). Please leave comments saying if it works for you or if it does not. If your data gets corrupted after this for whatever reason (you get mismatch errors in backtesting) just repeat the history deletion step.
If you would like to learn more about the limitations of backtesting, why a conjunction of live and backtesting is necessary to evaluate profitability and how you too can profit from long term profitable systems please consider buying my ebook on automated trading or subscribing to my weekly newsletter to receive updates and check the live and demo accounts I am running with several expert advisors. I hope you enjoyed the article !