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.

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.
Popular Stories
Apple today released iOS 17.0.2 and iPadOS 17.0.2 updates, with the software coming five days after the releases of iOS 17.0.1 and iPadOS 17.0.1. Today's iOS 17.0.2 and iPadOS 17.0.2 updates arrive as build 21A351 and can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update. Note that iOS 17.0.2 was previously made available for iPhone...
Apple previously announced that macOS Sonoma will be released this Tuesday, September 26. The free software update includes many new features and changes for the Mac, including the five that we have highlighted below. In addition to these five features, we have shared the full release notes for macOS Sonoma below for a complete overview of everything new. Desktop Widgets macOS Sonoma...
Complaints about heat issues with the iPhone 15 Pro models are not related to TSMC's 3-nanometer node that was used for the A17 Pro chip, according to well-respected Apple analyst Ming-Chi Kuo. Kuo says that overheating could be caused by "compromises made in the thermal system design" that allowed Apple to cut down on the weight of the iPhone 15 Pro models. Kuo says that the reduced heat...
The iPhone 16 series is expected to gain an additional capacitive button, known internally as the "Capture Button." Codenamed "Project Nova," the button is likely to be one of the main selling points of the iPhone 16 lineup, assuming it gets past the initial testing phase. The Capture Button is located on the same side as the Power button, only positioned slightly lower - where the mmWave cutout...
Apple could be preparing to release a seventh-generation iPad mini before the end of the year, based on a new report by DigiTimes. In an article discussing stagnating global tablet demand in the second half of 2023, the Taiwan-based outlet forecasts an uptick in Apple's share of the market owing to orders for a "small-size" iPad in the fourth quarter. From the report (see bold): In the...
Apple today released macOS 14 Sonoma, the newest version of the operating system that runs on the Mac. macOS Sonoma has been in beta testing for several months, and it is compatible with the 2019 and later iMac, the iMac Pro, the 2018 and later Mac mini, the 2018 and later MacBook Pro, the 2019 and later Mac Pro, and the Mac Studio. The macOS Sonoma update can be downloaded for free on...
Top Rated Comments
Admittedly, I was doing some pretty intense word processing at the time, so I can see why macOS would flake out.
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.