Apple introduced a bug with macOS 10.15.6 and it's killing virtual machines

macOS Catalina (Image credit: iMore)

What you need to know

Some users report that their Macs are crashing when running virtualization apps.
The issue began after they installed macOS 10.15.6.
VMWare's support team says it's Apple's fault and there is no workaround.

Apple's macOS Catalina update hasn't been one of its best and the release of macOS 10.15.6 hasn't helped matters. Several people have reported issues with Macs crashing while using virtualization apps like VMWare – and it's all Apple's fault.

That's according to a VMWare tech support thread (opens in new tab) after the company's engineers did some digging, as spotted by MacRumors. And it doesn't make for good reading.

We have narrowed down the problem to a regression in the com.apple.security.sandbox kext (or one of its related components) included in macOS 10.15.6 (19G73), and we have now filed a comprehensive report with Apple including a minimal reproduction case which should allow them to easily identify and address the issue.

It sounds like the folks at VMWare have done their job. Now it's over to Apple. To add insult to injury it doesn't sound like there's any scope for a workaround here, either. Although restarting Macs that run virtualization software regularly is one potential short term solution.

We'll keep investigating possible workarounds to see if we can pop out a point release with a mitigation... To Be Determined. (In all honesty, it isn't looking good, but we've come up with some mighty creative workarounds in the past, so I'll never say never.)

Hats off to VMWare for doing the legwork here!

Apple is set to launch macOS 11 Big Sur in a couple of months and it's currently available for developers to test. Here's hoping for a smoother launch this time around rather than a repeat of the Catalina fun we've seen of late.

Oliver Haslam has written about Apple and the wider technology business for more than a decade with bylines on How-To Geek, PC Mag, iDownloadBlog, and many more. He has also been published in print for Macworld, including cover stories. At iMore, Oliver is involved in daily news coverage and, not being short of opinions, has been known to 'explain' those thoughts in more detail, too.

Having grown up using PCs and spending far too much money on graphics card and flashy RAM, Oliver switched to the Mac with a G5 iMac and hasn't looked back. Since then he's seen the growth of the smartphone world, backed by iPhone, and new product categories come and go. Current expertise includes iOS, macOS, streaming services, and pretty much anything that has a battery or plugs into a wall. Oliver also covers mobile gaming for iMore, with Apple Arcade a particular focus. He's been gaming since the Atari 2600 days and still struggles to comprehend the fact he can play console quality titles on his pocket computer.