Mac Prohibitory Symbol on Startup

Overview

Mac prohibitory symbol (circle with a line through it) on startup means the Mac found a startup disk but macOS is not compatible or is corrupted.

Key Details

• Circle with a line displayed during boot
• macOS found on the disk is incompatible with this Mac
• System files may be corrupted beyond repair
• Different from the flashing folder (which means no disk found)

Common Causes

• macOS version incompatible with Mac hardware
• System files critically corrupted
• Target Disk Mode detected incompatible OS
• Boot sector or core system files damaged

Steps

1. 1Boot into Recovery Mode (Command+R) and reinstall macOS
2. 2Reset NVRAM and try booting again
3. 3Use Internet Recovery (Option+Command+R) if local Recovery fails
4. 4Erase and clean install macOS from Recovery

Tags

More in Startup

Frequently Asked Questions