Hello,
We have identified the error which was a bug in the picai_eval pipeline. The bug is now fixed but unfortunately I'm currently out of office and will only be able to upload a new validation container to Grand Challenge on Tuesday. In the meantime you could try submitting to the tuning leaderboard. Since the validation set is a lot larger it's less likely this error will occur. I'm sorry for the inconvenience. Please also note that the challenge dead line has been extended to the end of November, as announced in the challenge homepage.
Thank you for understanding and please let me know if you have any other questions.
Regards,
Natália Alves