Hi Dali, I can't reproduce this bug, but I remember there being a similar bug in the past. With the old bug there was an error that occurred which (for some reason) resulted in an empty datatable being displayed instead of the error. Can you check your webserver error logs (or piwik logs) for any clues? If there's nothing there, would you mind sending me a private message with the hierarchical data that won't be flattened?
thanks!
thanks!