Rotting Apples: macOS Sierra PDF Bugs Get Worse in 10.12.2

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On the eve of the release of macOS Sierra, Fujitsu released a warning to users of its ScanSnap scanners that issues with the operating system’s handling of PDFs could cause data loss for users with scanned documents. While the risk of Sierra PDF data loss later turned out to be more limited than initially feared, Fujitsu’s compatibility warning was just the beginning of PDF-related issues for Apple’s latest Mac operating system, issues that actually seem to be getting worse with the recent macOS Sierra 10.12.2 update.

macos sierra pdf bugs

Sierra PDF Bugs: Blame It On iOS

As noted by TidBITS publisher Adam Engst, Apple’s attempts to create a common foundation for PDF viewing and editing between macOS and iOS have resulted in a number of problems in Sierra, to the point that developers of third party software now recommend users avoid Apple’s own Preview app in order to minimize the risk of data loss.

According to Christian Grunenberg, lead developer of veteran Mac app DEVONthink, the problem stems from Apple’s premature release of its rewritten PDFKit API, a release which both eliminated some existing features and broke compatibility on others, causing issues for a range of third party apps.

Apple wants to use a common foundation for both iOS and macOS. However, it was released way too early, and for the first time (at least in my experience) Apple deprecated several features without caring about compatibility. And to make things worse, lots of former features are now broken or not implemented at all, meaning that we had to add lots of workarounds or implement stuff on our own. And there’s still work left to be done.

“Sloppy Code and Indifference”

While Sierra PDF woes have existed since the operating system’s initial launch, the most troubling aspect for both users and developers is that the situation seems to be getting worse. Jon Ashwell, developer of the Bookends bibliography app, reports that macOS Sierra 10.12.2 is “a disaster” in terms of PDF compatibility, causing crashes whenever a user opens a PDF containing annotations. Mr. Ashwell and other developers have attempted to resolve the issue with Apple by submitting bug reports and other information, but claim that the company has remained mostly silent. “I’ve never seen such a sorry case of sloppy code and indifference from Apple,” Mr. Ashwell told TidBITS.

The relatively good news for some Sierra users is that the issues appear to be limited to apps relying on PDFKit; apps using other PDF libraries, such as Smile Software’s PDFPen, seem to be unaffected at this time. But this apparent immunity only applies if the user steers completely clear of Preview and other PDFKit-reliant apps. If the user, or anyone the user shares their PDFs with, edits the documents in Preview or other PDFKit apps, issues like the loss of an OCR layer or corruption of the document itself may occur. As a safeguard against these problems, users should create copies of their PDFs to ensure that the original document is preserved in the event that the document is inadvertently edited in an app like Preview.

The next Sierra update, 10.12.3, is currently being tested, but there is as yet no confirmation that Apple has corrected these issues.

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pbw – I put Sierra on about 5 weeks ago right before my publishing deadline and my email world pretty much stopped. I think for years I got complacent and just accepted all the spam that never seemed/seems to stop. I’m basically too understaffed to take the time to research as much as I’d like on all the various programs that would make my life easier. I live in these 4 programs: Indesign, Photoshop, Apple Mail, Contacts & Calendar. I’ve always dreaded upgrading and hold off as long as possible. Two years ago, I hired a designer to take the… Read more »


I’m glad I’m not the only one who has had a gutful of Apple’s comtempt for its Mac buyers.

I’m having serious problems with Mail in Sierra. Does anyone know of any discussions about

After the initial update to OS Sierra version 10.12.2 my laptop is not the same anymore. Its so slow and taking up a lot of memory, freezing up my laptop and system has run out of application memory. I’ve freed up some space and deleted some files but no luck.

Apple is really good at messing things up when they do a software upgrade.


Kira, I too feel quite negative about Apple’s direction. So I understand and I don’t think any apology on your part is warranted. If Apple thinks that the iPhone community of users would be anywhere near as loyal as us long time Mac customers then I think they are in for a rude awakening some day. The sad thing is that Apple is a publicly traded company and will continue to focus on the high profit areas until profits dip enough to warrant a change in direction. My point is with all of the money Apple has they should not… Read more »


PDFs are often archival documents resulting from scans of paper documents. They are as irreplaceable as photos in many cases. Applications (PREVIEW) and code that CORRUPT PDF documents are not acceptable. The fixes should be the highest priority at Apple and take weeks, not years.

Rick Hyman

Jonn Ashwell developer of Bookends said,”I’ve never seen such a sorry case of sloppy code and indifference from Apple” Unfortunately, we *do* have a history of this in the past few years. I think specifically of the terrible TextKit Apple introduced with iOS 7. In prior versions, TextKit was built on top of WebKit, which draws web content. Yes, logic says it should have been the other way around. The first iteration of TextKit in iOS 7 did not cause data loss, but severe text display issues. Various discussion lists are full of developer comments indicating all sorts of work-arounds… Read more »

This cannot be true. Apple states that it has great desktops in its roadmap; thus, that sentiment should extend to the OS that runs its Macs as well. Ergo, and I repeat, this cannot be true. /sarcasm intended/ All I have to say about Apple today and its love affair with iOS and the consumer space is Fsck You. I’m really jaded with Apple’s indifference to the needs and wants of prosumers, power users, and professionals who champion the Mac platform. I supported Apple from its inception, even through lean times when it was unfashionable to work with the Mac.… Read more »


My experience with Preview has been somewhat spotty; it seems to have problems with a number of pdfs that pass through my system. I general find an alternate PDF view to read them because of this; and I’m not even on Sierra yet. “We Don’t Care. We Don’t Have to. We’re the Phone Company.” Scary how similar Apple is becoming to the old phone company. It is beginning to disturb me that they are having to verbally reassure people that they are not ignoring the Mac and their core software (sort of like listening to a politician), but I’m more… Read more »


“I’ve never seen such a sorry case of sloppy code and indifference from Apple”

“We Don’t Care. We Don’t Have to. We’re the Phone Company.”

Hopefully that kind of rot isn’t spreading across the company. Apple, you HAVE GOT to get PDFs right. Mission critical, especially within your own apps and system APIs.

Dorkus Maximus

“Rotting Apples”? What FUD artist wrote this headline? Is this CNET or Mac Observer?