Intel-based Macs that include an integrated T2 chip include new security features “Secure Boot” that control what startup disks can be used. These models include:

* iMac Pro
* Mac mini (2018)
* MacBook Air (2018 and later)
* MacBook Pro (2018 and later)
* Mac Pro (2019)
* iMac (2020)

In order to use the Mac OS X Basic and Mac OS X Minimal Profiles and eDrive volume created with Techtool Pro 11 and later along with macOS 10.14 Mojave or greater, you will need to start up to your Mac’s Recovery HD and change some settings in the Startup Security Utility.

1. Turn on your Mac, then press and hold Command (⌘)-R immediately after you see the Apple logo. Your Mac starts up from macOS Recovery.
2. When you see the macOS Utilities window, choose Utilities > Startup Security Utility from the menu bar.
3. When you’re asked to authenticate, click Enter macOS Password, then choose an administrator account and enter its password.
4. In order to start up from external disks, choose the “Allow booting from external media” and “No Security” options.

An example of the Startup Security Utility interface is below.