JK Rowling's The Casual Vacancy ebook suffers glitches
US-based shoppers who bought the new JK Rowling novel have been hit by a glitch that made it difficult to read.
A formatting problem meant that when The Casual Vacancy was downloaded to some e-readers it could only be viewed in a large size that showed a limited number of words per page, or in tiny-sized type.
The publisher, Hachette, has released a fixed version.
But many users who had pre-ordered the title will have been affected.
The novel topped several ebook charts ahead of its release due to high interest in JK Rowling's first novel for adults, following the success of her Harry Potter series.
A statement from Hachette acknowledged that it was responsible for the fault which prevented font and margin sizes being adjustable.
"As soon as Hachette was made aware of these issue, a replacement file was uploaded to all ebook retailers," the publisher said in a statement.
"Hachette has requested each retailer contact their customers directly about reloading their ebook.
"Any consumer who purchased the ebook on Thursday... who has not heard from the retailer, should contact them and request that their ebook be reloaded. No consumer should have to repurchase the ebook."
The Casual Vacancy's UK publisher, Little Brown, confirmed that users in the country had not been affected.
Several users - some of whom had already taken issue with the ebook's $17.99 (£11.22) pre-order price - complained about the error on ebook store review pages.
"I got an electronic reader so that I could make the font large enough for me to read and I'm stuck with a damned magnifying glass," wrote one user on Barnes & Noble's site.
Another shopper wrote on Amazon's store: "The Hachette Publishing Group should be ashamed for having so little quality control on such a big release. For shame. Buy the paper edition."
The news site PaidContent, which first reported the issue, noted that strict embargoes imposed on the book's release might have prevented the retailers' staff picking up on the problem before the ebook went on sale.
Users affected by the mistake can now manually force their devices to install the update. But one industry watcher said the issue should not be underplayed.
"It was a massive frustration for the true fans who wanted the book to be delivered to them at one minute past the embargoed time, and it shows that publishers are not quite on the money when it comes to ebook formatting," Philip Jones, editor of trade magazine The Bookseller, told the BBC.
"This kind of mistake is not as unusual as it should be, and publishers need to get it right from the beginning. In the physical book world an error like this is much more rare.
"But I don't think it will have affected sales of the book or readers enjoyment of it once they have got it."