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 “Fix 'Installation Failed' When Updating macOS” remains unresolved, identify the first numbered step that produces a different result and preserve that screen, file, log, or message. Recheck the specific account, permission, storage, connection, source-media, or hardware prerequisite above, then follow only the matching Apple Support recovery path; do not combine unrelated resets, bypasses, unofficial installers, or third-party repair tools.
Sources and verification
Checked against official documentation on . Scope: macOS.
Reviewed against the linked first-party guidance; interface labels can vary by current app, service, or operating-system version.