Mac OS · macOS
Fix 'Installation Failed' When Updating macOS
Source-checked About 10 minutes
Answer
Check storage, internet access, and Apple System Status, retry from Safe Mode, repair the startup disk in Recovery, and reinstall macOS without erasing if needed.
Record the exact error
Note the installer name and message, connect power, confirm free space, and use a stable internet connection.
Retry safely
Restart, install from System Settings > General > Software Update, then retry from Safe Mode if it fails again.
Repair the startup disk
Back up, start Recovery, run Disk Utility First Aid on the startup volumes, and retry the installation.
Reinstall without erasing
Use Reinstall macOS in Recovery next. Erase only when you intentionally need a clean reset and have a verified backup.
Video walkthrough
If it does not work
- If the issue continues, record the exact error and compare it with the linked Apple Support guidance before resetting, reinstalling, changing permissions, or deleting data.
Sources and verification
Checked against official documentation on . Scope: macOS.
Follow the linked first-party guidance if labels differ after a platform or app update.