[Solved]Mac Starts to Prohibitory Symbol After macOS Big Sur Update

macOS Big Sur will be the next version of Mac OS, announced at WWDC 2020. It is again named after the landscape in California but skips the macOS 10 version to macOS 11. According to the macOS Big Sur preview from Apple, the new features mainly sit in the new control center, interface and notification center as well as improved apps such as Safari, Messages and Maps.

However, the new OS doesn’t always bring good news. Here is a list of macOS 11 known issues and fixes. In this article, we will specifically discuss the Mac booting into a prohibitory symbol on the screen after macOS Big Sur update.

What does it mean when your Mac boots to a prohibitory symbol?

When a circle with a line cross it appears on your Mac’s monitor instead of a login screen or desktop, it is very likely that your Mac doesn’t support running macOS Big Sur. Even though the OS can be successfully downloaded on the startup disk, the relevant hardware is unable to install the OS nor launch it for use. It is a very typical problem people encounter when they update their Mac computers.

What Macs are compatible with macOS 11 Big Sur?

It is recommended to check the system requirements before you upgrade your Mac, especially before a major OS version upgrade. Some models can run macOS Catalina but are not necessarily compatible with macOS Big Sur.

macOS 11 Big Sur can be running on Macs including:

• MacBook models from early 2015 or later
• MacBook Air/Pro models from 2013 or later
• Mac mini models from 2014 or later
• Mac Pro models from 2013 or later
• iMac models from 2014 or later
• iMac Pro models

By checking the Mac’s hardware information, you can go to Apple logo and About This Mac to know your Mac model.

How to fix the prohibitory problem issue?

Now you know macOS Big Sur is not the right OS to run on your Mac, but how to get rid of the downloaded macOS 11 files and restore the Mac? Don’t panic. The steps are very easy.

Step 1: Boot your Mac into Recovery Mode.

You need to start or restart your Mac and immediately press down Command, Option and R keys together. Release the keys until you see a loading screen. The booting process will be a lot slower than usual. Then you will be led to the OS X Utilities or macOS Utilities window.

Step 2: Back up files from the Mac.

If you are afraid of data loss, you can use Target Disk Mode or data recovery software to get the important files off the Mac first.

Step 3: Reinstall OS

You can choose to format the hard drive first in Disk Utility and reinstall OS. Also, you can directly reinstall OS by selecting Reinstall OS X or macOS and clicking Continue. You just need to follow the wizard to finish the reinstallation.

Conclusion

Before you update to a newer OS, do remember to check the compatibility first in case you will boot to a prohibitory symbol during the installation. If the issue is happening, you can easily restore the Mac to a bootable state. macOS 11 Big Sur is a beta now and will be released to public in fall 2020, so it is recommended to upgrade after it is officially released if your Mac is compatible.

Kenneth

Kenneth is a proud native of sydney, born and raised there. However, he pursued his education abroad and studied in Australia. Kenneth has worked as a journalist for almost a decade, making valuable contributions to prominent publications such as Yahoo News and The Verge. Currently, he serves as a journalist for The Hear Up, where he focuses on covering climate and science news. You can reach Kenneth at [email protected].