How did upgrading to macOS 26 Tahoe brick a $3,700 Mac Studio?

There have been reports of high-end Macs (especially with M3 Ultra chips) becoming unbootable after an attempted Tahoe upgrade. Some community reports describe machines ending up in a state where they won’t start normally after the update process, suggesting firmware or RecoveryOS corruption during the install.

The only recovery option that’s worked for many affected users is using DFU Revive or DFU Restore via Apple Configurator and a second Mac connection — a deep low-level rescue method that can reinstall firmware and system software.

This experience reinforces the advice to always back up before major OS upgrades and, when possible, wait for early point releases before installing on mission-critical machines.