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 Forum: macOS Catalina

Popular Stories

iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching in Three Months With These 12 New Features

Saturday June 14, 2025 5:45 pm PDT by
The iPhone 17 Pro and iPhone 17 Pro Max are three months away, and there are plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of June 2025:Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone X through iPhone 14 Pro have a...
iPadOS 26 App Windowing

Apple Explains Why iPads Don't Just Run macOS

Friday June 13, 2025 7:46 am PDT by
iPadOS 26 allows iPads to function much more like Macs, with a new app windowing system, a swipe-down menu bar at the top of the screen, and more. However, Apple has stopped short of allowing iPads to run macOS, and it has now explained why. In an interview this week with Swiss tech journalist Rafael Zeier, Apple's software engineering chief Craig Federighi said that iPadOS 26's new Mac-like ...
iphone 16 pro models 1

17 Reasons to Wait for the iPhone 17

Thursday June 12, 2025 8:58 am PDT by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models simultaneously, which is why we often get rumored features months ahead of launch. The iPhone 17 series is no different, and we already have a good idea of what to expect from Apple's 2025 smartphone lineup. If you skipped the iPhone...
Logitech Logo Feature

Logitech Announces Two New Accessories for WWDC

Friday June 13, 2025 7:22 am PDT by
Alongside WWDC this week, Logitech announced notable new accessories for the iPad and Apple Vision Pro. The Logitech Muse is a spatially-tracked stylus developed for use with the Apple Vision Pro. Introduced during the WWDC 2025 keynote address, Muse is intended to support the next generation of spatial computing workflows enabled by visionOS 26. The device incorporates six degrees of...
iOS 26 Screens

Here Are All the iOS 26 Features That Require iPhone 15 Pro or Newer

Thursday June 12, 2025 4:53 am PDT by
With iOS 26, Apple has introduced some major changes to the iPhone experience, headlined by the new Liquid Glass redesign that's available across all compatible devices. However, several of the update's features are exclusive to iPhone 15 Pro and iPhone 16 models, since they rely on Apple Intelligence. The following features are powered by on-device large language models and machine...
CarPlay Liquid Glass Dark

Apple to Let iPhone Users Watch Videos on CarPlay Screen While Parked

Thursday June 12, 2025 6:16 am PDT by
Apple this week announced that iPhone users will soon be able to watch videos right on the CarPlay screen in supported vehicles. iPhone users will be able to wirelessly stream videos to the CarPlay screen using AirPlay, according to Apple. For safety reasons, video playback will only be available when the vehicle is parked, to prevent distracted driving. The connected iPhone will be able to...
iOS 26 on Three iPhones

Hate iOS 26's Liquid Glass Design? Here's How to Tone It Down

Wednesday June 11, 2025 4:22 pm PDT by
iOS 26 features a whole new design material that Apple calls Liquid Glass, with a focus on transparency that lets the content on your display shine through the controls. If you're not a fan of the look, or are having trouble with readability, there is a step that you can take to make things more opaque without entirely losing out on the new look. Apple has multiple Accessibility options that ...
Mac Studio Feature

Apple Begins Selling Refurbished Mac Studio With M4 Max and M3 Ultra Chips at a Discount

Thursday June 12, 2025 10:14 am PDT by
Apple today added Mac Studio models with M4 Max and M3 Ultra chips to its online certified refurbished store in the United States, Canada, Japan, Singapore, and many European countries, for the first time since they were released in March. As usual for refurbished Macs, prices are discounted by approximately 15% compared to the equivalent new models on Apple's online store. Note that Apple's ...
iOS 26 Feature

Apple Seeds Revised iOS 26 Developer Beta to Fix Battery Issue

Friday June 13, 2025 10:15 am PDT by
Apple today provided developers with a revised version of the first iOS 26 beta for testing purposes. The update is only available for the iPhone 15 and iPhone 16 models, so if you're running iOS 26 on an iPhone 14 or earlier, you won't see the revised beta. Registered developers can download the new beta software through the Settings app on each device. The revised beta addresses an...

Top Rated Comments

eji Avatar
68 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)
5097842 Avatar
68 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
68 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
68 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
68 months ago

('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
68 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)