Overview

• Users attempting to run older macOS versions on M4 Macs encounter a black screen and failed boot.
• The issue arises during the early kernel boot process, affecting all major virtualization software.
• M1, M2, and M3 Macs do not face this problem and can run older macOS versions in virtual machines.
• Developers and users relying on older macOS for testing should consider this limitation before upgrading.
• A fix would require Apple to release updated IPSW files for older macOS versions, which is unlikely.