If you're trying to leave your review on Amazon, Goodreads, Barnes & Noble, iBooks/iTunes, Smashwords, Google Play, or Kobo and do not meet their criteria for reviewing, you'll likely be greeted with an error message on their site.
If you find yourself in this situation, please contact the author of the ARC. The websites that you're required to review on are set by the author and will vary by their needs. Only they can change this for you.
Booksprout has no control over this matter as we cannot help you get your review on external websites (as much as we'd like to be able to do that!) and we also cannot go against the author's wishes.