Mac Boots to Circle with Line Through It 🚫 & How to Fix It

Rarely, you may encounter a Mac that boots to a screen that shows a circle with a line through it, or a circle with a slash through it.

If you encounter a Mac booting into a circle with a line through it, read along to understand what is happening, and how to resolve the problem.

The Mac circle with a slash through it symbol looks kind of like this emoji, except it’s grayscale: 🚫

What does a Mac booting into a circle with line through it mean?

What the circle with a line through it means is that the Mac has found an operating system that is not compatible with the Mac itself, therefore it can’t boot MacOS.

Troubleshooting Mac Booting to Prohibited Symbol / Circle with Line Through It

There are a few reasons why the Mac may boot into a black screen with a prohibited symbol. Read along to learn how to fix it.

Disconnect All External Boot Disks or Installer Disks

The most common reason Mac users encounter this error is when attempting to use a bootable macOS installer drive, or an external boot disk, and the MacOS version is not capable of running on the particular Mac.

For example, if you attempt to use a macOS Monterey boot disk on a new Mac, it will not run but instead will show the circle with a line through it symbol on a black screen during system start.

Nonetheless, there are other reasons this symbol can appear too, and sometimes it shows up erroneously as well.

Repair the Disk

Sometimes the prohibitory symbol shows up due to boot error, or an error after a system software update (automatic or otherwise). This is usually easy to fix.

1. Shut down the Mac by holding the Power button down for 10 seconds until the computer turns off
2. Press the Power button again to turn on the Mac, then press and hold the Command+R until you boot into MacOS Recovery mode
3. From the MacOS Recovery menu, choose “Disk Utility” and select your hard drive, and choose to Repair the startup disk

Reinstall MacOS

Rarely, macOS needs to be reinstalled on the Mac. Fortunately you can choose to just reinstall the system software itself. You should have a backup available of your data, so that you do not lose anything important in this process.

1. Shut down the Mac by holding the Power button down for 10 seconds until the Mac is off
2. Press the Power button again to turn on the Mac, then press and hold the Power Button (Apple Silicon) or Command+R (Intel Mac) until you boot the Mac into MacOS Recovery mode
3. From the MacOS Recovery menu, choose to Reinstall MacOS and walk through the steps

You can learn more about reinstalling MacOS on Apple Silicon Macs or on Intel Macs if interested.

If you repaired the disk, disconnected all external drives, reinstalled MacOS, and continue to experience issues and the prohibitory symbol when you boot up a Mac, you may need to contact official Apple Support for further assistance.