Mac Prohibitory Symbol Fix: MacBook Shows Circle With Slash on Startup

Encountering the dreaded prohibitory symbol (a circle with a line through it) on your Mac during startup? This indicates a problem with your macOS installation, likely due to incompatibility or corruption. Don't panic; this guide offers several solutions to get your Mac back up and running.

Understanding the Problem:

The prohibitory symbol signifies that your startup disk has an incompatible or corrupted macOS installation. This prevents your Mac from booting correctly. Common causes include corrupted system files, outdated or incompatible macOS versions, and issues with the startup disk itself.

Solutions:

Here's a breakdown of troubleshooting steps, from simple restarts to more advanced recovery methods:

1. Safe Mode Restart: This starts your Mac with minimal extensions, helping identify software conflicts.

   1. Restart your Mac.
   2. Hold down the Shift key until the Apple logo appears.
   3. Release Shift when the login window appears. Log in.

2. Verify Startup Disk: Ensure your Mac is booting from the correct disk.

   1. Power on and immediately hold down the Option key.
   2. Select "Macintosh HD" (or the name of your startup drive) from the Startup Manager.
   3. Press Enter.

3. macOS Recovery Mode Repair: This powerful tool checks for and repairs system file corruption.

   1. Turn on your Mac.
   2. Press and hold Command R.
   3. Choose "Reinstall macOS" from macOS Utilities.
   4. Follow the on-screen instructions.

4. Reset NVRAM/PRAM: This resets certain system settings that might be causing the problem.

   1. Power down your Mac.
   2. Power on and immediately hold Option Command P R for about 20 seconds.
   3. Release the keys.

5. Run First Aid (Disk Utility): This scans your startup disk for errors and attempts to repair them.

   1. Restart your Mac, holding Command R to enter Recovery Mode.
   2. Open Disk Utility from macOS Utilities.
   3. Select your Macintosh HD.
   4. Click "First Aid" and then "Run."
   5. Restart your Mac after the process completes.

6. Contact Apple Support: If none of the above steps work, contact Apple Support for further assistance. They can help diagnose hardware or software problems.

Visual Aids:

Recommendation: Reinstalling macOS in Recovery Mode is often the most effective solution for resolving startup issues caused by the prohibitory symbol. If you're uncomfortable performing these steps yourself, consider seeking professional assistance.

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