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macOS 10.15.4 Catalina Supplemental Update Fixes FaceTime Bug

Apple has released a supplemental update for macOS 10.15.4 Catalina (see “Apple Releases macOS 10.15.4 Catalina, watchOS 6.2, tvOS 13.4, and iOS 13.4 for HomePod,” 24 March 2020). As with iOS 13.4.1, the highlight of macOS 10.15.4 Catalina Supplemental Update is a fix for FaceTime problems introduced in the last update. The supplemental update:

  • Fixes a bug that prevented Macs running macOS 10.15.4 from engaging in FaceTime calls with devices running iOS 9.3.6 or OS X 10.11.6 El Capitan and earlier.
  • Prevents USB-C ports in your Mac from becoming unresponsive.
  • Resolves an issue that caused the 2020 MacBook Air to hang in Setup Assistant when disconnecting and reconnecting a 4K or 5K external display.
  • Stops Microsoft Office 365 accounts from repeatedly prompting you to enter a password.

The supplemental update has no published CVE entries.

The update pane for macOS 10.15.4 Supplemental Update

You can install the 1.01 GB macOS 10.15.4 Supplemental Update from System Preferences > Software Update. On his Eclectic Light Company blog, Howard Oakley said, “This is the smallest macOS update that I have ever analysed in detail, suggesting that those bugs were severe in their effects.”

If you’ve already installed macOS 10.15.4 and are likely to run into any of the bugs it fixes, it’s probably worth installing this update soon. Otherwise, you can wait until it’s convenient—as you’ll see in the comments, a few people have anecdotally had problems with it.

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Comments About macOS 10.15.4 Catalina Supplemental Update Fixes FaceTime Bug

Notable Replies

  1. I did it right away, because of the USB C fix, if that’s what it is.

    I have a late-2018 Mac mini – so, one of the new ones with four Thunderbolt ports. I never use more than one or two of the ports (mostly for backup disks) but I rotate through them to see whether they’re working.

    That seemed a little over-fussy until in late February or early March, one of them turned out to be not working. I was still on Mojave then, but hoping (without really believing) that maybe it was a software problem, I installed Catalina when 10.15.4 came out.

    And it worked! Still, with this supplemental update notes mentioning the USB C fix, it seemed good to do it right away.

    At least it didn’t make it worse. I’m typing on the port that used to be broken.

  2. Please report on any surprise Mail fixes, or any verifications that the problems still exist.

  3. Sorry, nothing along those lines this time. At least one of those issues was fixed by 10.15.4. Have you suffered a problem? The majority of users have are not seeing any issues, but many are unhappy with some of the new features, which I doubt will ever be allowed to go back to the way they were.

  4. Apologies if I’m reading this all wrong, but to me that almost makes it sound like most Catalina issues are just folks having trouble to adjust.

    But if I take just what has been discussed here on TidBITS I’d say many users have suffered from mail issues (some as serious as actual loss) and it’s these persistent issues without fixes from Apple (despite how many updates now?) that are causing much of the upset and Catalina remorse, not few superficial changes that might take getting adjusted to (64 bit was well announced and most came prepared).

    I don’t think Adam, Josh, et al. are known to resist change or advise people to hold off because of change, but IIRC they have cautioned users several times about potentially severe mail issues if you use and decide to go Catalina. Precisely because I know how restrained they are with such warnings against “moving ahead”, I take their cautions re: Catalina quite seriously. And personally, that does really bug me because I will most likely want to get a new MBP soon and then Catalina will have to be dealt with one way or another.

  5. Here’s a problem that a fairly technical friend of mine ran into. After installing the supplemental update, his Mac was going to force him to go through the steps that would be necessary from a new install: choose a localization, set up Internet access, set up Siri, and then it made him create an admin user.

    He backed out and was able to see that all his data was still on the Data volume, which he backed up via Carbon Copy Cloner. Once he had that backup for additional peace of mind, he let the Mac do its full setup process, including creating a new admin user. It seemed to be fine after that, albeit with a new admin user in addition to his normal one, but to be safe he then booted into macOS Recovery and reinstalled Catalina. Again, things seem fine afterward.

    So, just a data point, but if this happens to you, make sure you have a backup and then proceed (since there doesn’t seem to be any alternative).

  6. Thanks Adam! (I’m the “fairly technical friend” Adam was referring to.)

    I decided to let the update happen today on my 2 week old 2018 Mac Mini (3.2 GHz 6-Core i7, 32 GB RAM, Radeon RX 5700 XT 8GB eGPU) and I left everything plugged in during the update (RAIDs, Drobo, eGPU, and a bunch of USB-C drives). As far as I can tell it worked just fine, except I had to re-install my SoftRAID drivers after the update.

  7. Thanks for the report, Dave! As with @alvarnell, I’m hesitant to warn against this update in a big way because the problems seem to be few and far between, if fairly extreme.

    The hard part with identifying problems with updates is that a certain number of problems will occur simply because of so many piece of the operating system being touched during the update. A disk error, previously corrupted data that hadn’t been accessed recently, cosmic rays flipping a bit—any of these things can cause a problem. And even worse, physical and digital problems occur all the time, so they could simply happen to occur during an update, with no actual relationship to the update other than time of day.

    Which is not to say that anyone having problems is imagining them; just that it can be hard to know when to lay the blame at the feet of the update unless there are sufficient similar reports.

  8. Lots of enterprise IT’s are just starting to apply the update today and so far report on Slack MacAdmins only a smattering of kernel panics and observations that the T2 firmware update appears to take a long time with the screen blacked out, but no “bricks” so far.

    Howard Oakley wrote about his experience with the update Last Week on My Mac: Surprise Supplemental Update.

    So my best guess is that the only folks with any issue are using T2 Macs and that they panic when they see the black screen and are power cycling them before the T2 firmware update is finished.

  9. Thanks for that background.

    I think Howard’s post again serves as a reminder just how helpful it would be if Apple had some kind of indicator to tell the user that, despite a black screen for prolonged periods of time, their Mac was still updating its firmware and to just be patient. Just blinking a light (could be the caps lock key for portable Macs) would be good enough.

    The problem with the status quo, and what makes it so dangerous, is that there is ZERO user feedback. If somebody loses their patience or perhaps they are reminded of an older install that crashed, bar any feedback, they could be tempted to interrupt the firmware update attempting to recover from a “crash”. And because of the T2 and the way it serves as a secure SSD controller that means you’d be entering a world of pain (to quote a great movie line).

    If there were some kind of simple user feedback to just tell people that everything was progressing, it would be much easier to tell people to be patient and just wait. Even if you’re a hard core Mac pro, if your Mac hasn’t done anything at all as far as you can tell in the last hour, how do we know what is really going on (ssh login of course wouldn’t be an option in this case)?

  10. More evidence of Apple doing distributed software testing.

  11. There is further discussion of major problems here:

    A bricked device while the Apple stores are closed sounds very scary. I’m not installing 10.15.4 at all, much less the supplemental update on my home computer.

    (In fact, on my work machine I’ve still not seen a single reason to update to 10.15. Still running Mojave, 32 bit apps and all, and loving it.)

  12. I haven’t read of this issue with non-T2 Macs and all of the bricked Mac users that were willing to admit it said they held the power button down after seeing a black screen for what seemed to them to be a long time.

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