If you haven't been able to download a report for a game, it may be due to one of your questions in the game not having any correct answers (we noticed in all cases this was a multiple response question type). This caused an issue determining the points scored for the player, which caused an error when attempting to download the report.
This has now been fixed, so you can download the reports from these games. Note, however, that the scores won't show because of the original error calculating the score.
We have now improved the validation to saving the game so it doesn't let you save a question with no correct answers.