The Charlie/Novel Trilogy

While not the official name of the trilogy, this book series takes place in a different continuity from the original FNaF games. While the books do share similar names and events, it's not made to "solve" anything in mind. Some elements and characters from these books do appear in the later games and Fazbear Frights. The books are indeed canon as they are written and approved by Scott, but the timeline does not align to the games or even Frights.