Apple Releases macOS Catalina 10.15.4 Supplemental Update With FaceTime Bug Fix

Apple today released a supplemental update to macOS Catalina 10.15.4, two weeks after releasing the macOS Catalina 10.15.4 update with Screen Time Communication Limits and Real-Time Apple Music lyrics.

macos catalina wallpaper
The ‌macOS Catalina‌ 10.15.4 Supplemental Update can be downloaded from the Mac App Store for free using the Update feature in the System Preferences app.

The new software introduces a fix that caused Mac computers running ‌macOS Catalina‌ 10.15.4 to be unable to participate in FaceTime calls with devices running iOS 9.3.6 and earlier or OS X El Capitan 10.11.6 and earlier.

Apple says it also addresses an issue with Office 365 accounts, fixes a bug that could cause a USB-C port to become unresponsive, and addresses a problem that caused the 2020 MacBook Air to hang during Setup Assistant or when connecting or disconnecting a 4K or 5K display. Full release notes for the update are below:

‌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

‌macOS Catalina‌ 10.15.4 could be one of the last updates to the ‌macOS Catalina‌ operating system as Apple transitions to working on macOS 10.16, which is unnamed as of yet.

Related Roundup: macOS Catalina

Top Rated Comments

eji Avatar
8 months ago
I was notified of this update right after my machine kernel panicked for the third time this week. It's a regular occurrence since the .4 update.

Admittedly, I was doing some pretty intense word processing at the time, so I can see why macOS would flake out.
Score: 23 Votes (Like | Disagree)
TallGuyGT Avatar
8 months ago
I really wish Apple would push out a supplemental update for the kernel panic issue. I haven’t had any issues with Catalina until 10.15.4, now regular kernel panics during sleep. This is on a clean install of 10.15.4 as I thought it would be stable by now.
Score: 14 Votes (Like | Disagree)
DesertNomad Avatar
8 months ago
They really need a two year cycle on major OS versions - Catalina is still broken in many ways and they will simply move on instead of fixing it. I have been using Macs since System 6.0.3 on a Mac IIcx in 1989 and the current OS cycle is a mess. I miss Steve Jobs every day.
Score: 14 Votes (Like | Disagree)
cericsmith Avatar
8 months ago
I'm shocked and frustrated that Apple doesn't address this in the 10.15.4 Supplemental Update... This has got to be impacting many professional users!

I jumped through huge hoops to reinstall with 10.15.3 today to fix the kernel-panic/lockup that strikes when accessing external storage (ThunderBay 6, SoftRaid XT). I was getting hard locks randomly when hitting disks, even if it wasn't the RAID-5 TB6 -- just moving files from the MBP 15" SSD to an external SSD, both APFS formatted.

It's been a HUGE pain... first I thought it was the RAID -- took days chasing that down, multiple wipe/restores/verification passes... then I saw the original bug report on MacRumors re: KP's with 10.15.4... I moved the TB6 to a Mac mini also running 10.15.4 to verify the problem was also striking there (without any MBP-related power/nap/sleep complications), and it was indeed...

Apple didn't have 10.15.3 available to grab via Terminal, either...

The good news is that (if you can "track down" a working 10.15.3 full installer), installing over either 10.15.4 OR 10.15.5b1 works fine. Both of my Macs are back and running w/o problem on the same set of discs... I've moved many TB's of data in the last 5 hours since I rolled it back with no issues.

I will not be applying this or any other Catalina updates until this issue has been confirmed to be fixed.
Score: 10 Votes (Like | Disagree)
loby Avatar
8 months ago


[IMG width="251px"]https://images.macrumors.com/images-new/macrumorsthreadlogo@3x.png[/IMG] ('https://www.macrumors.com/2020/04/08/apple-releases-macos-10-15-4-supplemental-update/')

Apple today released a supplemental update to macOS Catalina 10.15.4, two weeks after releasing the macOS Catalina 10.15.4 update ('https://www.macrumors.com/2020/03/24/apple-releases-macos-catalina-10-15-4/') with Screen Time Communication Limits and Real-Time Apple Music lyrics.



The macOS Catalina 10.15.4 Supplemental Update can be downloaded from the Mac App Store for free using the Update feature in the System Preferences app.

The new software introduces a fix that caused Mac computers running macOS Catalina 10.15.4 to be unable to participate in FaceTime calls with devices running iOS 9.3.6 and earlier or OS X El Capitan 10.11.6 and earlier.

Apple says it also addresses an issue with Office 365 accounts, fixes a bug that could cause a USB-C port to become unresponsive, and addresses a problem that caused the 2020 MacBook Air to hang during Setup Assistant or when connecting or disconnecting a 4K or 5K display. Full release notes for the update are below:macOS Catalina 10.15.4 could be one of the last updates to the macOS Catalina operating system as Apple transitions to working on macOS 10.16, which is unnamed as of yet.

Article Link: Apple Releases macOS Catalina 10.15.4 Supplemental Update With FaceTime Bug Fix ('https://www.macrumors.com/2020/04/08/apple-releases-macos-10-15-4-supplemental-update/')

I hope Apple makes the decision to just "camp" on the island for another year instead of going somewhere else so they can just get this OS stable instead of introducing 10.16. Social distancing on Catalina island might be good for the OS.. :)
Score: 6 Votes (Like | Disagree)
sw1tcher Avatar
8 months ago


I was notified of this update right after my machine kernel panicked for the third time this week. It's a regular occurrence since the .4 update.

Admittedly, I was doing some pretty intense word processing at the time, so I can see why macOS would flake out.

I was writing a paper on the Mac and it was like beep beep beep beep beep and then like half my paper was gone. And I was like "Huh?" It devoured my paper. It was a really good paper. And then I had to write it again and I had to do it fast so it wasn't as good. It's kind of... a bummer.
Score: 5 Votes (Like | Disagree)

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