Apple's new models of Mac mini, MacBook Air and MacBook Pro have received good reviews, not least thanks to the new M1 processor, which offers a real performance improvement. But new models usually have some teething problems, and this time is no different.
According to MacRumors, some users who tried to restore their new computer in order to remove unwanted software before installing macOS 11.0.1 found that having deleted the data they were unable to reinstall macOS.
Some Mac users on receiving their new Mac prefer to wipe it and do a clean install of the operating system without certain included apps. However, after deleting the SSD they found that they were unable to reinstall macOS and saw a message: "An error occurred while preparing the update. Failed to personalise the software update. Please try again."
According to Apple, the problem only affected users who had deleted their Mac before updating to macOS Big Sur 11.0.1. Reinstallation was no longer possible for these users and they saw the message "An error occurred while preparing the update. Failed to personalise the software update. Please try again."
It seems the devices were shipped with a version of macOS Big Sur 11.0.1 in which macOS Recovery did not work. According to Apple, a system restore should work again without any problems after the last Big Sur update.
Initially the only way to fix this problem was to connect the Mac to another Mac and use the Configurator 2 software. Instructions for this method can be found on the Apple website.
However, on 21 November Apple released a support document that describes how to restore a new M1 Mac if problems are encountered.
One solution is to create a bootable installer for macOS, something you can do using another Mac if you have not already done one before recovery. If a macOS Big Sur installer is used then a new installation is then possible.
Another method outlined by Apple uses Terminal and requires booting into macOS Recovery with a few corrections necessary to enable installation. Follow the instructions on Apple's website (link above).
Recovery is started by holding down the start button when starting the system. You then see the message 'Loading startup options' and should be able to select the recovery system.
Next start Terminal (via Utilities) and you have to enter the commands as detailed in Apple's instructions. First you have to reset the password with 'resetpassword', then delete the Mac again using the Recovery Assistant.
The Mac is now reactivated, but you also have to enter a longer command in Terminal - which you can call up from the rescue system via Safari. A total of 17 individual steps are necessary.
In some cases the terminal reports an error; this must be corrected using another command. Apple outlines the steps necessary if you choose this method.