Apple Releases macOS Catalina 10.15.6 Supplemental Update With Virtualization Bug Fix

Apple today released a supplemental update for macOS Catalina 10.15.6, with the update coming a month after the original launch of macOS Catalina 10.15.6.

macos catalina wallpaper
The ‌‌macOS Catalina‌‌ 10.15.6 Supplemental Update can be downloaded from the Mac App Store using the Update feature in the System Preferences app.

According to Apple's release notes, the update fixes a problem that could cause virtualization apps like VMware to crash. It also fixes an issue that could cause the 2020 iMac to appear washed out after waking from sleep. Apple's full release notes are below:

macOS Catalina 10.15.6 supplemental update includes bug fixes for your Mac.

- Fixes a stability issue that could occur when running virtualization apps
- Resolves an issue where an iMac (Retina 5K, 27-inch, 2020) may appear washed out after waking from sleep

macOS Catalina 10.15.6 will likely be the last update to the macOS Catalina operating system as Apple transitions to macOS Big Sur, the newest version of macOS set to be released in the fall.

Related Forum: macOS Catalina

Popular Stories

apple tv 4k new orange

New Apple TV Expected Later This Year With These New Features

Saturday July 12, 2025 3:09 pm PDT by
A new Apple TV is expected to be released later this year, and a handful of new features and changes have been rumored for the device. Below, we recap what to expect from the next Apple TV, according to rumors. Rumors Faster Wi-Fi Support The next Apple TV will be equipped with Apple's own combined Wi-Fi and Bluetooth chip, according to Bloomberg's Mark Gurman. He said the chip supports ...
iphone 16 pro ghost hand

5 Reasons to Skip This Year's iPhone 17 Pro

Thursday July 10, 2025 4:54 am PDT by
Apple will launch its new iPhone 17 series in two months, and the iPhone 17 Pro models are expected to get a new design for the rear casing and the camera area. But more significant changes to the lineup are not expected until next year, when the iPhone 18 models arrive. If you're thinking of trading in your iPhone for this year's latest, consider the following features rumored to be coming...
iPhone 17 Pro in Hand Feature Lowgo

iPhone 17 Pro Coming Soon With These 16 New Features

Friday July 11, 2025 12:40 pm PDT by
Apple's next-generation iPhone 17 Pro and iPhone 17 Pro Max are only two months away, and there are plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models. Latest Rumors These rumors surfaced in June and July:A redesigned Dynamic Island: It has been rumored that all iPhone 17 models will have a redesigned Dynamic Island interface — it might ...
Apple Watch Ultra 2 Complications

Apple Watch Ultra 3: What to Expect

Sunday July 13, 2025 10:30 am PDT by
The long wait for an Apple Watch Ultra 3 is nearly over, and a handful of new features and changes have been rumored for the device. Below, we recap what to expect from the Apple Watch Ultra 3:Satellite connectivity for sending and receiving text messages when Wi-Fi and cellular coverage is unavailable 5G support, up from LTE on the Apple Watch Ultra 2 Likely a wide-angle OLED display that ...
iphone 16 pro pro max

iPhone 17 Pro Models With BOE Displays Will Be Sold in China Only

Thursday July 10, 2025 11:59 pm PDT by
iPhone 17 Pro and iPhone 17 Pro Max models with displays made by BOE will be sold exclusively in China, according to a new report. Last week, it emerged that Chinese display manufacturer BOE was aggressively ramping up its OLED production capacity for future iPhone models as part of a plan to recapture a major role in Apple's supply chain. Now, tech news aggregator Jukan Choi reports...
top stories 2025 07 12

Top Stories: iPhone 17 Pro Rumors, iOS 26 Beta 3, and More

Saturday July 12, 2025 6:00 am PDT by
The iOS 26 public beta release is quickly approaching, while developers have recently gotten their hands on a third round of betas that has seen Apple continue to tweak features, design, and functionality. We're also continuing to hear rumors about the iPhone 17 lineup that is now just about right around the corner, while Apple's latest big-budget film appears to be taking off, so read on...
11th gen ipad blue

Apple to Launch New Low-Cost 11-Inch iPad in the Spring

Friday July 11, 2025 3:40 am PDT by
Apple will launch a new 12th generation entry-level iPad in the spring of next year, according to Bloomberg's Mark Gurman. Apple is said to have two versions of the entry-level 11-inch iPad in development, codenamed J581 and J582. These could refer to different storage capacities – in which case, Apple may be planning to drop the existing lowest capacity option. The current iPad 11 is...

Top Rated Comments

ignatius345 Avatar
64 months ago

A fired Apple employee will not starve. I don't demand perfection from my family because they don't work for Apple as professionally paid software people. Somebody failed and is responsible that there was field exposure. Apple got lucky that this wasn't a data corruption bug.

OS development is only as complex as what you develop. What they are changing in a point release this late in the development cycle should be fixing bugs and thoroughly testing them. The general expectation of incremental point releases is that the higher the number the less changes involved. That small amount of change should be thoroughly tested, especially if it's to such core service as the HV FW.

Somebody fsck'd up big time. Heads have to roll.
Jesus. Give it a rest. Both of you. Nobody cares. I’m reading through this thread trying to find salient info about bug fixes, not listen to your rants about whether people should be fired or not. Hopefully a moderator will come in and delete all of these (and this message as well). Thank you.
Score: 23 Votes (Like | Disagree)
Colonel Blimp Avatar
64 months ago

Somebody fsck'd up big time. Heads have to roll.
Whose heads? The programmer who wrote the code? An individual software tester who failed to catch the bug? The person who wrote the test plan? The QA manager who supervised the testing? The QA director?

How about the Product Manager who signed off on the release? The director of software engineering? The VP of Software?

Or how about the executives who decided to allocate only so many resources to software testing, while maintaining pressure to meet an ambitious feature release schedule?

In any company, the responsibility for releasing buggy software goes all the way up the chain, not just theoretically but in actual practice. The danger of demanding that heads roll is that 1) the heads probably won’t belong to the people responsible for creating the conditions that lead to the release of buggy software, 2) the people who replace your decapitated developers will have less experience with the software you’re developing, and 3) your developers may become more concerned about covering their posteriors (a singularly inappropriate metaphor for someone facing decapitation) than about working together to release high-quality software.

Don’t get me wrong. As someone who used to run software QA for a living, I’m inclined to think that people should be serving jail time for some of the software bugs I keep reading about, but actually deciding who to fire or hang or sacrifice to the Red God isn’t entirely straightforward, nor perhaps entirely helpful.
Score: 13 Votes (Like | Disagree)
chucker23n1 Avatar
64 months ago
So, about two and a half weeks between VMware narrowing it down to a sandbox issue, reporting it to Apple, and Apple releasing a fix. That's not so bad.
Score: 11 Votes (Like | Disagree)
CJ Dorschel Avatar
64 months ago
I've been a Mac user for almost 20 years yet this is the first time I have never updated my systems to the latest OS. I've held off on 10.15 but am considering updating as Apple has begun to drop support for certain aspects of 10.14 (security updates, etc will continue of course). I've been experiencing issues on two Mac Pro's that haven't been resolved with weeks of online research, clean installs, and Apple tech leading me to consider updating to 10.15.

My biggest concern is access to root as Apple continues to extend SIP. I've always disabled SIP and Gatekeeper as I require read/write access for development and third party apps. Certainly this it not something everyone should do and doing so is always with risk yet is a necessity for my personal needs and I utilize other precautions, etc.

That stated, my biggest concern is read/write access to root as Apple created two volumes for Applications - User and System. I've created a script that mounts the drive for read/write, assigns the necessary permissions, then deletes it. I've used this on my MacBook Pro for development work which is now running Big Sur.

My concerns with 10.15:

- Will this be necessary in case my system needs to be restarted? (I rarely do so unless necessary)
- Has Apple locked the ability to mount and change root permissions with incremental 10.15.x updates?

Don't even get me started on Big Sur. Running it on my MacBook Pro for development and struggling to adjust to the UI in addition to SSV. I completely understand Apple's focus on security especially for novices/everyday users, yet their focus on locking the system down further with each release makes it difficult for third party developers to maintain their apps which is most likely Apple's true intentions as they want to force developers to utilize the Mac App Store. Given there are ways to easily bypass Apple's security measures - granted they've made the processes more difficult - and users have already found backdoors in Big Sur, I wonder if there are better methods for security measures than what Apple has been implementing since SIP and Gatekeeper were introduced.
Score: 10 Votes (Like | Disagree)
jchap Avatar
64 months ago

Hope somebody lost their job.
It seems a bit cruel to wish that someone would lose their job (accompanied with all the resulting hardship) over this. It must have been an inconvenience to you and to many other people to deal with this bug, but is it reasonable to attribute the problem to one person in specific, or to make one person take the blame for something Apple might not have known about or fully understood the implications of to begin with? Do you also expect this same level of perfection from your friends, your family and those you deal with in everyday life?

Make no mistake—I, too, get upset and irritated when software bugs interrupt my productivity and enjoyment of technology. I’ve complained a lot to Apple over the years, and logged countless support cases for numerous products, both software and hardware. When something is not to my liking or when it causes me inconvenience as a user, I will complain.

That said, I also realize that with something as complex as an operating system, there’s not just one person pulling the strings behind the curtain, so to speak. It’s a team effort, and sometimes mistakes are made. No manufacturer has ever released a flawless product without blemish, one which operates perfectly in every way. In the end, it’s up to the end user to make sure their bases are covered, so that when a particular piece of software or hardware they use does not function properly, they have a means of recovering.
Score: 8 Votes (Like | Disagree)
Belle Pomme Avatar
64 months ago
My MacBook Pro also has that washed-out problem too, so I hope it helps.
Score: 7 Votes (Like | Disagree)