- Starting with macOS 28, encrypted Mac OS Extended (HFS+) volumes will no longer be supported; only unencrypted versions will remain compatible.
- Users must decrypt or reformat encrypted legacy volumes to APFS or APFS (Encrypted) for continued use with macOS 28 and later, with data backup recommended.
- macOS 26 may notify users about incompatible encrypted Mac OS Extended disks, and steps are provided to check volume format and encryption status via Disk Utility.
- Apple encourages transition to APFS, its modern file system with built-in encryption, as part of ongoing system updates and compatibility improvements.