Fix com.apple.launchd.peruser Crash Loop on macOS

Symptoms

Users experiencing the com.apple.launchd.peruser crash loop may notice the following:

• Repeated system notifications about launchd crashing
• Console logs filled with com.apple.launchd.peruser error entries
• Mac becomes sluggish or unresponsive
• Applications fail to launch or crash unexpectedly
• System may require forced restarts

Root Causes

The com.apple.launchd.peruser process is responsible for managing user-level daemons and agents. A crash loop occurs when:

• Corrupted or misconfigured plist files in ~/Library/LaunchAgents/
• Third-party software installs faulty launch agents
• Permissions issues on user library folders
• macOS update conflicts with existing user agents
• Malware or adware injecting malicious plists

Step-by-Step Fix

Step 1: Boot into Safe Mode

1. Restart your Mac and hold the Shift key immediately after the chime.
2. Release when the login window appears (you'll see 'Safe Boot' in red).
3. Log in and observe if the crash stops. If yes, the issue is likely a third-party launch agent.

Step 2: Identify Problematic Plists

1. Open Terminal from Applications > Utilities.
2. Run:

   ls ~/Library/LaunchAgents/

3. Look for unfamiliar or recently added .plist files (e.g., com.unknown.app.plist).
4. Check modification dates:

   ls -lt ~/Library/LaunchAgents/

Step 3: Remove or Disable Suspicious Plists

1. Move suspicious plists to a backup folder:

   mkdir ~/Desktop/plist_backup && mv ~/Library/LaunchAgents/com.suspect.plist ~/Desktop/plist_backup/

2. Unload the agent if currently running:

   launchctl unload ~/Library/LaunchAgents/com.suspect.plist

3. Restart normally and check if the crash loop is resolved.

Step 4: Reset User Launchd

1. In Terminal, run:

   sudo launchctl reboot userspace

2. This resets all user launchd processes without a full reboot.
3. Alternatively, restart the Mac completely.

Step 5: Repair Permissions (macOS Mojave and earlier)

1. Boot into Recovery Mode (restart and hold Command+R).
2. Open Disk Utility, select your startup disk, and run First Aid.
3. For macOS Catalina and later, use:

   diskutil resetUserPermissions / `id -u`

   in Terminal after booting normally.

Alternative Fixes

• Create a new user account: If the crash is user-specific, create a new admin account and migrate data.
• Reinstall macOS: As a last resort, reinstall macOS from Recovery Mode without erasing data.
• Use EtreCheck: Run EtreCheck to identify problematic launch agents automatically.

Prevention

• Regularly review ~/Library/LaunchAgents/ for unknown plists.
• Install software only from trusted sources (App Store or verified developers).
• Keep macOS updated to avoid compatibility issues.
• Use ad-blockers and antivirus to prevent malware that may inject launch agents.
• Periodically run launchctl list to monitor user agents.

Additional Notes

If the crash loop persists after removing all suspicious plists, consider resetting NVRAM (Intel Macs) or checking for hardware issues. For Apple Silicon Macs, resetting SMC is not applicable; instead, ensure all third-party kernel extensions are updated. Always back up your data before making system changes.