Something I have just noticed today which has perplexed me:
When viewing an .AZW3 book in Calibre's ebook viewer the final page sometimes shows a blue square indicating that an image is missing. But there is no image missing.
My preferences are that the cover only shows at the front of the book and this is always shown. I don't understand why this blue square appears at the back of the book and I think it is related to the front cover (titlepage.xhtml).
When I right-click and inspect it there is one error:
Failed to load resource: Error opening C:/Users/sylvia/AppData/Local/Temp/calibre_bzn2yt/dtlx4k_ebook_iter/Images/cover.jpeg: No such file or directory
It only appears in Calibre's ebook viewer. It does not show at the end of Kindle for PC viewer.