Shortly after the launch of Apple’s new M1 Macs, we saw reports that attempts to restore and reinstall macOS on these machines could immediately result in an installation error that left your Mac non-functional.
Specifically, the error message will read: “An error occurred while preparing the update. Staff could not customize the software update. Please try again.”
Over the weekend, Apple sent detailed instructions to users experiencing this issue. Specifically, it appears that the issue occurs if you delete / restore your Mac before upgrading to macOS Big Sur 11.0.1.
If you deleted your Mac with Apple M1 chip before updating to macOS Big Sur 11.0.1, you may not be able to reinstall macOS from macOS Recovery. A message might say “An error occurred while preparing the update. Failed to customize software update. Please try again. “
Use one of these solutions to reinstall macOS. You should then be able to use macOS Recovery as expected when reinstalling macOS in the future.
Apple suggests that you create a bootable installer using another Mac. Otherwise, Apple describes a more technical 17-step process using Terminal to restore your M1 Mac to a functional state.
If you’re still having issues, Apple recommends contacting support, and you can also visit our ongoing forum thread where users are failing this specific issue.