Deleting system cache files while a download or install is active can corrupt the update. Cancel or wait for a stuck install to time out before clearing cache.
What you will achieve
Clear corrupted Software Update cache when macOS hangs at zero percent, repeats the same failed download, or reports insufficient space despite having room — then retry cleanly from System Settings.
Stuck updates often trace to partial downloads in /Library/Updates or cached metadata in user and system Library folders. Flushing these is safer than repeatedly force-restarting mid-install.
1) Confirm the symptom
Typical cache-related failures: download stuck at 0%, “An error occurred” immediately on retry, or the same update offered repeatedly after a failed install. Rule out genuine low disk space first via System Settings → General → Storage — you need at least 15–20 GB free for point updates, more for major upgrades.
2) Quit Software Update cleanly
- Open System Settings → General → Software Update.
- If a download is in progress, click the × or Cancel if available.
- Quit System Settings completely (Command+Q).
3) Remove cached update payloads (administrator)
Open Terminal from Applications → Utilities → Terminal and run:
sudo rm -rf /Library/Updates/*
sudo rm -rf /Library/Updates/ProductMetadataAuthenticate with your administrator password. These folders repopulate on the next update check — you are not breaking Software Update permanently.
4) Clear user-level Software Update cache
rm -rf ~/Library/Caches/com.apple.SoftwareUpdate*
rm -rf ~/Library/Caches/com.apple.commerce*No sudo needed for user Library paths. Log out and back in if System Settings still shows stale progress.
5) Reset Software Update preferences (optional)
sudo rm /Library/Preferences/com.apple.SoftwareUpdate.plist
sudo rm ~/Library/Preferences/com.apple.SoftwareUpdate.plistmacOS recreates these on next launch. Managed Macs may restore plist values from MDM — that is expected.
6) Retry from System Settings
- Reboot once (cold boot on Apple Silicon: Apple menu → Shut Down, then power on).
- Open System Settings → General → Software Update.
- Download and install again.
Intel Macs on flaky Wi‑Fi may benefit from Ethernet for the re-download. Apple Silicon Macs download arm64 packages exclusively — ensure you are not mixing installers copied from Intel Macs.
7) If cache clear alone fails
Boot into Recovery (Apple Silicon: hold power → Options; Intel: Command+R at startup), run Disk Utility First Aid on the internal disk, then choose Reinstall macOS without erasing. That refreshes system components without touching your data — distinct from cache clearing but often the next step.
Verify
Software Update downloads past 0%, completes install, and reports current version without re-offering the same failed update.