An error in the macOS recovery causes significant problems on ARM Macs: The attempt to reinstall the operating system on one of the Macs with Apple’s M1 chip currently fails with an error message, as several users report. After deleting the SSD and reloading macOS 10 Big Sur, the message appears that an error occurred while preparing the update, “the Personalizing the software update failed “- try again.

Restore only via second Mac Further attempts would, however, result in the same error message, according to affected users. Normal startup of the Mac is no longer possible at this stage. As things stand, the only way out is to repair or restore the Mac’s firmware using DFU mode – similar to what is known from iPhones, but more laborious: The firmware restore requires a second Mac with at least macOS 10. 15. 6 Catalina and the tool Apple Configurator 2, the can be downloaded for free from the Mac App Store.

To connect the two Macs, a USB-C to USB-C cable or – for Interoperability with older Macs – a USB-A to USB-C cable is required. The cable must support the transmission of data and power, emphasizes Apple. Thunderbolt 3 cables are not supported according to the manufacturer, but according to experience reports they still work.

Cumbersome procedure Das The cable must be plugged into a specific port on the Mac to be restored, as Apple states in its instructions, which are currently only available in English. In order to put the M1-Mac into DFU mode (Device Firmware Upgrade), a specific key combination must also be pressed directly after switching on. If the procedure described by Apple fails, users can fall back on a manual based on experience reports from Mr. Macintosh. Recovery via DFU mode and a second Mac is not new, it also works on all Macs with Apple’s T2 security chip.

Users of the new M1 Macs – MacBook Air, MacBook Pro or Mac mini – should initially refrain from reinstalling the operating system, as far as possible, until Apple has created a way to do this again normally via macOS recovery.

(lbe)