Djvu stopped working – KyBook 3 Ebook Reader Review

iOS 15.2 kybook 3 0.7.8 Opened a folder of djvu books with about 20 books. It worked fine. I was able to read the books. I added another 50 books to the folder. Now it shows the covers for some books and just the title for some, stating there was an error in processing. When I try to open any book to read, even ones that worked earlier, it says djvu kit error 1. The app is now totally unusable.
Review by 10pongal on KyBook 3 Ebook Reader.