macOS Catalina 10.15.4 gets a stability update – but reports claim it’s breaking some MacBooks

macOS Catalina
(Image credit: Apple)

Apple has deployed a supplemental update for the problematic macOS Catalina 10.15.4, fixing some issues – albeit not the most pressing ones, and the worrying thing is, we’ve seen multiple reports popping up online of this update causing fresh problems, from failing to install, to allegedly bricking machines.

This certainly seems like echoes of what we’ve seen in recent times with Microsoft badly fumbling updates for Windows 10, with fixes being applied, but introducing further new problems post-installation.

As spotted by 9 to 5 Mac, Apple says that the macOS Catalina 10.15.4 supplemental update improves the “stability, reliability, and security of your Mac”, as well as introducing some specific fixes.

Sadly, the kernel panic glitches and system crashes reportedly caused by Catalina 10.15.4 aren’t among them – at least not according to Apple, or the feedback we’ve seen online that indicates these flaws remain – but there are fixes for a FaceTime bug, and a solution for an issue whereby a USB-C port can become unresponsive.

There’s also a fix for those who have a MacBook Air 2020 and have been experiencing problems when disconnecting or plugging in a 4K or 5K external monitor, as well as crashes with the Setup Assistant. And a bug where Office 365 repeatedly requests your password been resolved, too.

Bricking Macs?

Obviously those are very useful fixes, even if they aren’t the solutions that some folks are more desperately clamoring for going by online posts across various forums. However, scanning across those threads, there’s another more worrying specter – and that’s reports of this new supplemental update causing serious issues of its own, as we mentioned at the outset.

One 9 to 5 Mac reader observed that it killed a 2016 MacBook – apparently it won’t even power up – and the update also had problems with a 2012 Mac Mini, which ran ‘insanely slow’ when it eventually finished installing, requiring a restore from Time Machine.

Hopping over to Apple Insider’s forum, there are reports that “this one borked my 2012 iMac”, and the update also allegedly bricked a 2018 13-inch MacBook and a 2019 16-inch MacBook Pro.

There are indications that installing the update can be troublesome, too, which also appear on other threads, with the installation process failing for some. (Note that it’s a lengthy update process, by all accounts, taking the best part of half an hour to install – at least on some people’s machines.)

Further machine-breaking issues are aired over at Apple’s own forums, and several threads at MacRumors, with the latter including reports of a 2019 MacBook Pro dying and a 2018 13-inch MacBook similarly being rendered unusable, among other incidents.

Of course, we should underline that these are just anecdotal reports on various online forums, but nevertheless, there are enough of them to give us cause for concern that at least some users may be running into serious difficulties here.

Also note that in the interests of balance and perspective, there are plenty of reports of the supplemental update running just fine for many folks also chiming in on these threads.

macOS Catalina users can grab the supplemental update via System Preferences > Software Update, but the more cautious might want to hold off for now, perhaps, until we find out more about whether there are any serious issues lurking within this update.

Darren is a freelancer writing news and features for TechRadar (and occasionally T3) across a broad range of computing topics including CPUs, GPUs, various other hardware, VPNs, antivirus and more. He has written about tech for the best part of three decades, and writes books in his spare time (his debut novel - 'I Know What You Did Last Supper' - was published by Hachette UK in 2013).