MacOS Catalina 10.15.4 Supplemental Update Released with Bug Fixes

Apr 8, 2020 - 12 Comments

MacOS Catalina supplemental update

Apple has released MacOS Catalina 10.15.4 Supplemental Update for Mac users running macOS Catalina.

The new supplemental update includes a few bug fixes, including resolving a problem with FaceTime calls that was also patched in the iOS 13.4.1 and iPadOS 13.4.1 updates. The full release notes accompanying the MacOS Catalina 10.15.4 Supplemental Update are available further below.

How to Install MacOS Catalina 10.15.4 Supplemental Update

All updates to macOS can be downloaded from the Software Update preference panel. Back up the Mac before installing any system software update.

  1. Go to the  Apple menu, choosing “System Preferences”
  2. Select “Software Update”, and then choose to download and install MacOS Catalina 10.15.4 Supplemental Update

The Mac will require a reboot to complete installation, it will do that automatically.

Optionally, Mac users can also download the Supplemental Update as a packager installer from Apple.

Direct Download for MacOS Catalina 10.15.4 Supplemental Update Package Installer

Using a package installer for supplemental updates is basically the same as using a combo update or any other package based software update that is directly downloaded from Apple. Simply launch the package and install it. As always, you’ll want to backup your Mac before doing so.

‌macOS Catalina‌ 10.15.4 Supplemental Update Release Notes

“‌macOS Catalina‌ 10.15.4 supplemental update improves the stability and security of your Mac.

– Fixes an issue where Mac computers running ‌macOS Catalina‌ 10.15.4 could not participate in ‌FaceTime‌ calls with devices running iOS 9.3.6 and earlier or OS X El Capitan 10.11.6 and earlier

– Resolves an issue where you may repeatedly receive a password prompt for an Office 365 account

– Fixes an issue where ‌MacBook Air‌ (Retina, 13-inch, 2020) may hang in Setup Assistant or when disconnecting and reconnecting a 4K or 5K external display

– Resolves an issue where a USB-C port in your Mac may become unresponsive”

It’s unclear if the macOS 10.15.4 Supplemental Update addresses any of the kernel panics, random restarts, and system crashing problems that have been reported by some Mac users with the macOS 10.15.4 update, and there is no mention in the release notes.

Separately, Apple has also released watchOS 6.2.1, iOS 13.4.1 for iPhone, and iPadOS 13.4.1 for iPad, each of which comes with the same FaceTime bug fix and addressing a few other smaller bugs.


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Posted by: Paul Horowitz in Mac OS, News


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  1. Thomas says:

    Be careful for this update! I got tired of facing lots of bugs after the 10.15.4 update. All of the apps responded very slow, especially the chrome and mail. Sometimes the macbook pro can’t work after the wake up. The internet is badly connected unless I restart the machine. I’m ready to downgrade to mojave now. This Catalina waste me a lot of working time. Enough!

  2. Joel says:

    My wife’s 2018 MBA was “bricked”. I’d installed the Combo the night before, but it still showed the update in Sys Prefs. She saw it and clicked to install it. At some point the screen turned to “off”, a normal phase in OS installs, but it never came back. And until I found an Apple Support article about Revive/Restore the T2 Firmware, nothing did anything!

    It’s a bit of a stretch, but mainly just requires having another Mac with a USB-C port and the standard MacBook USB-C charging cord, and following directions. And a bit of patience as there is not a lot of feedback while the T2 Firmware is restored.

    Her “brick” showed up in Configurator after the appropriate key press and hold incantation, and though I got an error in Configurator that the Restore process had timed out, the Air booted several minutes later. It then showed me the Internet Recovery dialog, and I reinstalled the current macOS Catalina.

    Be aware that this process does reset the firmware which also erases the data from the drive. There is also a Revive process, but I chose to Restore as I did want to reinstall the OS from scratch and I did have several Time Machine backups to go back to.

    After the Catalina install, we did use the Migration Assistant offered upon booting into Catalina and restored the last backup. Restore did take several hours, but the computer is running very well now. I really thought it was gone, that the best alternative at that point was to order a 2020 Air for her. Very pleased to have it back.

    The other 5 computers onto which I installed the Combo are running great.

    Good luck everybody!

  3. Amr OKa says:

    Power point & google chrome atoped working

  4. John Merrill says:

    Beware. This “update” almost bricked my iMac. I’m not alone.

  5. Kamryn says:

    Since updating this with supplemental version of Catalina, I can no longer backup my files to my external hard drive. I backup to this external HD once a week, and I’ve only had this drive for about 4 months. Never any Time Machine problems until this update.. anybody else having this issue? It’s stuck on “Preparing backup…”

    I’ve tried every troubleshooting method I can find, and my only conclusion is that it’s related to this update.

  6. Leo says:

    After applying the supplemental update my machine worsen: Now it boots, allows login, and then freezes and reboots again. HD was check. I need to check memory to discard HW problems.

  7. Robert Kalmus says:

    would like to know if the Catalina update had addressed the mac os kernel panic* problem that so many folks have??

    *The Mac OS kernel panic problem=the computer randomly goes into sleep mode and takes over 2 minutes to resume play…..

  8. seopuglia says:

    You said “It’s unclear if the macOS 10.15.4 Supplemental Update addresses any of the kernel panics, random restarts, and system crashing problems that have been reported by some Mac users with the macOS 10.15.4 update, and there is no mention in the release notes.”…so what we have to do?

  9. Christian Miller says:

    I attempted to install the update but about halfway through my computer shut down and it bricked my 2018 13 inch MacBook. No power, no fans coming on and off or anything when pressing and holding the power button. It was plugged and fully charged while updating. Anyone else having this problem? Also attempted to do an SMC reset to no avail still won’t turn on. I am sending it in for repair. I would hold off updating unless you want to risk losing your computer for a week.

  10. Mateenah says:

    Question: Can you use Microsoft word, excel, etc. on the Catalina upgrade?

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