For some reason, Book Of Amnesia only works on initial load of the game, any reloading of a save causes the book to become absolutely unusuable when buying a new one, and if you have a usable one in your 'inventory' when loading a save, it causes an error trying to use it.

The mod RPG Items (0.18.9) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event rpg_items::on_gui_click (ID 1)
rpg_items/rpg_framework.lua:63: attempt to call field 'func' (a nil value)
stack traceback:
rpg_items/rpg_framework.lua:63: in function <rpg_items/rpg_framework.lua:4>