Faced with recurrent kernel panics and an inexplicable problem on the first boot after installing a minor macOS update, Adam Engst opts for a Level 2 clean install when upgrading to macOS 13 Ventura. What’s a Level 2 clean install? And did it work?

Signing certificates for macOS installers have expired, so Apple consultants and IT admins who maintain troubleshooting toolkits containing older installers will need to download new copies.

If you’re running macOS 10.13.3 High Sierra, and you restart, it’s possible that you’ll see an Installation Log screen and an error telling you that the macOS installation couldn’t be completed. Here’s how to recover.