Two ePub books that I've bought won't open in Books.app in macOS Mojave 10.14. The books have social DRM (personal information added to the content of the book), and I don't think this should be a problem for Books.app. If I rename the epub extension to zip, then I can unzip the file using the unzip command. Using the Finder doesn't work somehow. Other books open normally.

Looking at the contents, I see that it uses XHTML inside an OEBPS folder, while other books use HTML in an OPS folder.

What is the reason that Books.app doesn't open these ePub files? I can read them OK with Calibre.

  • What is social DRM? Books.app doesn't support epubs with drm afaik Commented Jan 20, 2019 at 19:48
  • Social DRM adds personal information to the content of the book. It is not like Adobe DRM which is an encrypted format. Like I said, I can unzip the contents, so it's "open".
    – SPRBRN
    Commented Jan 20, 2019 at 21:42
  • Oh, kinda like the fingerprint being added to DRM-free content on iTunes? I feel like it should work as well then... Where did you buy the book from? The OPS should be an xml file describing it within the OEBPS folder if it isn't a folder itself. Also take a look at the META-INF files to check that there is no DRM. Commented Jan 20, 2019 at 21:50
  • Yes it's like a fingerprint. I can unzip it, then open all XHTML files in an editor. No technical limiting DRM, like I said.
    – SPRBRN
    Commented Jan 20, 2019 at 22:27

2 Answers 2


If your ebook indeed is unencrypted, you can try to open the ePub with the free Sigil.app (an ePub creator/editor) and write another copy to disk.

Sigil is able to repair a lot of structural problems. You can get a precompiled dmg as well as the full source code here.

I agree the "social DRM" should not pose any obstacle for using these eBooks with Books.app. But I suspect the "patching personal data into the eBooks" is done by an automated process, which simply went awry in your case. Maybe you even have some special characters in your identifying information (quotes, accents, ampersand, general unicode characters).

  • 1
    Thanks! I remember once downloading Sigil and not really getting it. Now I see what it can do. Just opening and saving did the trick.
    – SPRBRN
    Commented Jan 23, 2019 at 15:52

It's hard to know whether the "social DRM" or some other aspect of the epubs you mention is causing the problem with Books app. The best course is to let the publisher know so they can investigate if they wish and in the meantime use Calibre or another epub reader to read the books.

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