My settings went back to the defaults after BookyAI closed unexpectedly. Can that still happen?

From version 1.9.21 BookyAI saves its settings in a safer way. A save is written completely to a separate file first and only then replaces the old one, so a save cut short (by a crash, an update or a security program holding the file) can no longer leave a broken settings file behind. BookyAI also keeps a backup copy of your settings, and if the settings file ever cannot be read, it uses the backup instead of the defaults. Your API keys were never affected by this: they are stored separately and encrypted.