If Subjects and Dividers are missing from your Library, try the following steps:
Double check your internet connection.
Poor or unstable internet connection can cause organizers to temporarily not load.
Try closing and opening Notability. If that doesn’t work, completely close out Notability from the App Switcher and launch Notability again. This step may require a few repeated attempts before the Subjects and Dividers rebuild.
If the steps above don't help, reach out to our Support Team and we can assist further.