Hello,

I'm looking for hints on how to debug a problem with my backtest. The algorithm is in python. The backtest runs all the way from 2005 to 2020, and then fails with this error dialog:

73743_1611244283.jpg

There is no stacktrace. And this way of presenting the error message makes it impossible to see what the algorithm had been doing when the failure occurred.

I downloaded the logs. And the logs end with this:

2020-01-01 00:00:00 Data for symbol XP has been limited due to numerical precision issues in the factor file. The starting date has been set to 12/10/2019.
2020-01-01 00:00:00 Data for symbol XP has been limited due to numerical precision issues in the factor file. The starting date has been set to 12/10/2019.
2020-01-01 00:00:00 Runtime Error: Trying to retrieve an element from a collection using a key that does not exist in that collection throws a KeyError exception. To prevent the exception, ensure that the key exist in the collection and/or that collection is not empty. KeyError : (,)
2020-01-01 00:00:00 Algorithm Id:(d4979ac81b41ee413577b3dd4339067c) completed in 5719.30 seconds at 6k data points per second. Processing total of 34,140,354 data points.

Trying to run the algorithm in debug mode to try and catch the failure is impractical. How can I get some information about what's failing so that I can fix the problem? I've tried running the algorithm for a shorter duration, and the algorithm completes without problems. I've attached the backtest result below. And while the results show here, they do not show in the algorithm development environment.

Sunil