Invalid input: img/books/168_front_flap.jpg. Please provide a comma-separated list of id values, or a single id value. An id value is a positive whole number.
"If you are aware that you have made a mistake, then you should repeat your experiment. "Human error" is not a valid source of uncertainty. If you know that you did something "wrong", then why don’t you do it correctly? "
Invalid input: img/books/168_front_flap.jpg. Please provide a comma-separated list of id values, or a single id value. An id value is a positive whole number.