Did you open PoGo at any point to see what it was? If it was a Gen 2 pokemon, Pokefarmer did not support Gen 2 and would give that message. I hatched a Pichu and received the same thing and couldn't see the pokemon in "My Pokemon". It was just a blank space. As of later today, Pokefarmer has been updated to support Gen 2 and should be fine now. https://www.thebuddyforum.com/pokefarmer-forum/272194-pokefarmer-update-thread.html