I had a book by author Diamond Johnson on my Kindle under my KindleUnlimited account and I returned it on accident. To my surprise when I went to add it back I kept getting an error message and the book is not even listed on the authors page. Is there any reason a book would just vanish?
That happens all the time. I have over 4500 books in my library and the last time I checked (about 3000 books), over 500 were "orphans" - those that were no longer available.
There may be many causes:
The author may have updated the book with a new number (not available as an update) and the older number just "goes away".
The author or publisher may have intentionally pulled the book.
Someone may have reported a problem and Amazon pulled the book -- especially if it was a copyright issue.
There are other possibilities but those are the most common.
If it was with kindle Unlimited, you haven't really lost anything and there's nothing you can do. If you removed it by accident and you paid for the book, then contact Amazon. They may be able to restore it or help you out. Note -- they are not obligated to do ANYTHING if you removed the book yourself, even if it was an accident.
Rollback Post to RevisionRollBack
There is no such thing as a stupid question!
Corollary -- so long as you read before you post and stay on topic. :)