VMWare engineers report that macOS Catalina 10.15.6, which was released on July 15, has a bug that crashes Mac systems when using virtualization software such as VMWare or VirtualBox.
VirtualBox users have reported that macOS 10.15.6 crashes repeatedly when running virtual machines.
VMWare engineers have diagnosed the issue and filed a report with Apple offering a minimal reproduction case which should allow them to easily identify and address the issue.
A regression in the App Sandbox component of macOS 10.15.6 is reportedly leaking memory, causing the operating system to crash.
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.
We have not yet identified any workaround other than refraining from installing macOS 10.15.6, which is a bit painful (and the advice will come too late for anyone who finds this thread because they are already running into this problem), or shutting down your VMs whenever you aren’t using them and rebooting your host every day or every few hours or every hour, which is … ugggggh.
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.)
VMWare engineers suggest that users not install macOS Catalina 10.15.6 or to shut down virtual machines when they are not in use and to reboot the host computer as often as possible.