macOS 15 Sequoia had already deprecated Core Storage and encrypted HFS+ volumes, yet they mostly continued to function. Users sometimes had to manually unlock volumes at boot, and conversion to APFS was inconsistent, but data remained accessible. That changes with macOS 27 Golden Gate, which drops support entirely.
According to Wade Tregaskis, the new release cannot mount, convert, or erase Core Storage / encrypted HFS+ volumes. Disk Utility throws "com.apple.Disk Management.disenter error 49,153," while diskutil falsely claims volumes are already unlocked. A misleading boot dialog even warns that macOS 28 will end support, though the problem is present now.
The only partial success comes from running mount_hfs directly, which works read-only. Read-write mounting fails with "Resource busy" (EBUSY), and erasing volumes is impossible through normal tools. A workaround involving Gemini 4 Argon exists, but it is convoluted. The situation leaves expensive storage hardware effectively useless.
Source: Hacker News · Summarized by HeadlinesBriefing