Every macOS update fails during preflight personalization on my MacBook Pro (Mac15,6, Apple Silicon), currently on 27.0 build 26A5378j. It's failed on every build from beta 5 (26A5406e) through beta 7. Identical failure via Software Update and via startosinstall. It fails LOCALLY, before contacting Apple (gs.apple.com and gdmf.apple.com are both reachable with valid certs). Error (install.log + unified log): reaches PREFLIGHT_PERSONALIZE (~0.15), then aborts MobileSoftwareUpdateErrorDomain Code=1259 "failed to copy firmware identity" "could not obtain device identity information through SFR installer" SUMacControllerErrorPreflightPersonalizeFailed=7723 Root cause I've traced: an orphaned volume-group boot-policy directory in /System/Volumes/iSCPreboot/. ls shows two volume-group UUID dirs — the live one (matches diskutil info /) and an orphan (3D3287DE-...) with no corresponding APFS volume group (diskutil apfs list shows only one live group). Both date to Feb 2024. The preflight can't reconcile the System Recovery boot policy in the orphaned dir. Note: NOT caused by Erase All Content and Settings (unlike the commonly reported case). The orphan predates the beta, so any pre-existing second volume-group boot-policy directory reproduces it. It was harmless for ~2 years; macOS 27's stricter preflight rejects it. Ruled out (no effect): disk space, VPN, DNS, clock, Apple Account, refreshing the beta seed entitlement, reboot, Time Machine, re-downloading the installer, and Recovery reinstall (same 1259). Filed as FB24342236 — no response across beta 5, 6, 7. Questions: Is this a known issue with a planned fix, and in which build? Any supported recovery path that does NOT require a second Mac? (Recovery reinstall fails the same way.) Or is DFU Revive/Restore the only option? Will the public 27.0 release install on this machine, or hit the same preflight?