As always, I'm grateful for the work that is done to slowly repair broken Eidteic Memory books. That said, below you will find a number of books which are still bugged, and have been for quite a few patches. Some, like the
Tome of the Undaunted were bugged for at least a year when I first posted this list during the Elsweyr patch this time last year. I've done my best to accumulate descriptions of the issues surrounding each of these books and suggest post-quest locations when possible.
Tome of the Undaunted : Handbills, Posters, and Decrees
Not to be confused with its cousin, the Tome of the Undaunted (signed), which is perfectly fine and can be accessed in the Grahtwood Undaunted Enclave, this book has (from what I have been able to determine) absolutely no way to obtain it. It cannot be interacted with either before or during the quest "Taking the Undaunted Pledge," and is replaced by the signed version after the quest is completed (because the player signs it during the quest). One option to fix this issue is to place a copy of the unsigned version in one of the other Undaunted enclaves. Another option, since this is literally the same content as Tome of the Undaunted (signed) with the exception of the player’s signature, is to delete this book and just have the signed version be the only one, accessible after completing the associated quest.
Dead Water Riddle Fragment : Lore of Murkmire
Some patches ago, a post quest location was added for the Bright Throat Riddle Fragment, however no location has been added for this fragment as of yet. Like its Bright Throat counterpart, it is part of the quest "Whispers in the Wind," and is added and removed from the player's inventory without much warning or preamble. Having a post-quest location would be extremely beneficial for those who miss this small window.
Illuminus : Summerset Scrolls
This book is part of the quest "Illusions of Grandeur" in the Illumination Academy, and is recovered and shelved as part of the quest (after which it disappears). No post-quest location seems to exist, meaning that those who did the quest with another player who shelved the book instead have no way of obtaining it.
Naliara's Notes, Days 2, 8, 13, and 18;
King's Haven Territory Record, King's Haven Trade Record, and
King's Haven Scouting Record : Summerset Scrolls
These books are part of the quest "Savage Truths." During the quest, they are interacted with, the note pages disappear, and the plaques on which the records are kept become uninteractable. If a bug occurs where the books aren't added to the collection at this moment, it cannot be fixed. Thus, a post-quest location for them is needed.
Lirendel's Family Shrine : Summerset Scrolls
This only appears during the quest "A Duelist's Dilemma," on the statue in Tor-Hame-Khard. After the quest, the plaque is once again uninteractable. I'll need to do this quest again to remember where the duel takes place in order to be certain that a rubbing of it isn't left there, but I do not believe that will be the case.
For Captain Telomure; ; Journal of Justiciar Avanaire : Summerset Scrolls
Like the Pearl Research Notes, Log 3 that was just fixed, these books are located in Tor-Hame-Khard during the quest "Pearls Before Traitors" and disappear on quest turn-in. As interaction with these is not required for the quest, it makes it very easy for the player to miss their opportunity to retrieve these books for their collection. Therefore, it would be wise to either ensure that they remain present in their current locations after the quest is turned in or to give them a post-quest location, possibly outside the delve near Captain Telomure.
Sealed Letter : Mysteries and Clues
This book is used to begin the Dragonfall prologue from the Crown Store and, unlike many of the books for the prologue line, it lacks a post-quest location. As such, if something bugs out and the book isn't added to the Eidetic Memory log when it should be, there is no other option to add it. Possible post-quest locations could be one of the inn rooms where the player meets Kasura for the quest, or simply placing it in the upper room of the stable in the Valley of the Blades with the other books for the prologue.
If you have any questions, or would like any elaboration, please don't hesitate to ask.
As always, if anyone has anything to add or dispute, or can provide an in-game location I have missed, please don't hesitate to say so.