Return informative error when trying to save ranking round with 100+ images #373
Description
It is currently not permitted to include more than 100 images in a ranking round for usability and mental burden reasons. (see also #363 ).
Currently, the error is not very informative.
Please return a meaningful error to the organizer when they try to start the round with more than the required minimum (currently set at 100 I believe, please verify, may also be 50).