Little, Brown reports that the ebook file for JK Rowling's THE CASUAL VACANCY that the publisher provided US retailers on Wednesday had "issues," including affecting "the adjustability of font color and size and adjustability of margins." What that means, according to customer reports online, is that for many people the book displayed at a tiny font size that could not be adjusted. The company says that "as soon as Hachette was made aware of these issues, a replacement file was uploaded to all ebook retailers."
By customer accounts, and this report on PaidContent (with some screen shots), those issues made the file all but unreadable on a variety of major reading devices, including Kindles and Nooks. (It worked fine on the Kindle for iPad app, though.) Reports began with the sample file on Amazon forums and Nook forums
HBG suggested that "any consumer who purchased the ebook on Thursday before approximately 3:00pm Eastern who has not heard from their retailer should contact them and request that their eBook be reloaded." HBG did "request that each retailer contact their customers directly about reloading their eBook." They underscore that "no consumer should have to repurchase the ebook."