Hopefully, after doing the steps above, the message “an error occurred while preparing the installation of macOS” will no longer appear when you try to reinstall macOS Sierra or later. Now, proceed with trying to reinstall macOS. You may be asked to log in twice, depending on when the Safe Mode message appears.Restart your Mac, then immediately press and hold the Shift key until the login window appears.If you’re using an Intel-Based Mac, follow this procedure. Wait for your Mac to restart, and you should see “Safe Mode” when the login window reappears.

Press and hold the Shift key, then click Continue to Safe Mode.When completely shut down, press and hold the power button until “Loading Startup Options” appears.To boot your Apple Silicon Mac into Safe Mode, follow these steps. The process of rebooting in safe mode differs between Apple Silicon Macs and Intel-based computers.

The first thing that you should try is to boot your Mac into Safe Mode.

Let’s walk through some possible ways to resolve this error. This has happened often happens when reinstalling macOS Sierra, but it’s also been known to happen with newer versions. One example is a pop-up that reads, “an error occurred while preparing the installation of macOS Sierra.” Following that, you’re prompted to “try running this application again. On a somewhat frequent bases, installing or upgrading macOS halts with a message suddenly appearing.

How to wipe mac pro