Is it possible that you accidentally crafted something using the wrong anvil? Try separating all of your anvils and making something with each of them, you might also need to craft a potion using a regular bottle, and there are also recipes that need lava and honey if you haven't done those yet, your platform is also missing a skymill, hellforge and adamantite forge... Though I am not sure the nature of the trophy so all of these are guesses.