Prior to El Capitan, I used to sporadically see a few ‘random’ but consistently-repeating tech support issues. The most common were settings not “sticking”, file dialog windows not remembering their sizes, and St. Clair Software applications forgetting that a user had purchased a license. You might say “how are these in any way related?” Well, they all involve data stored using NSUserDefaults or CFPreferences, the built-in preference storage for macOS applications. It appeared that preference files would occasionally get corrupted – most commonly when an application auto-updated or when the user installed a macOS system update. The result was software not being able to retrieve previously-saved information. The incidents would often happen in waves – just after Apple released an OS update, or just after I released an update for one of my products (most noticeably Default Folder X, since it has the largest user base).

After Apple released El Capitan, most of this went away. I knew they’d been working on the application preference system for El Capitan because, in a few of the early developer betas, it was partially broken or changed in interesting ways. But by the release of 10.11.0, everything was working better than it ever had. Hooray for progress! Right?

And then came High Sierra. After two fairly quiet years, the preference-file-related problems started popping up again with increasing frequency. The most recent Default Folder X release seems to have resulted in a bunch of paid users being suddenly told they were running a trial version (the common thread is that they’re all running High Sierra). If you’ve been affected by this, I’m sorry! Unfortunately, nothing in Default Folder X’s license handling code has changed, it just suddenly can’t read your license information from its preference file, forcing you to re-enter it. I’ll be changing how Default Folder X saves its license info in future versions so this doesn’t keep happening because, yes, it’s really annoying.

With the apology done, I’m wondering – if you’re a developer, have you noticed similar issues with High Sierra? I never dismiss the possibility that I’m just doing something stupid, but with NSUserDefaults, there’s really not a whole lot to do wrong (feel free to correct me, of course). This has only happened to a very small percentage of my users, but there is a 100% correlation between the problems and High Sierra.