Quick Summary
Error 48 on macOS during a software update typically indicates a problem with downloading or verifying the update files. It suggests a corrupted download, an issue with the software update server, or a problem with the local update cache.
Common Causes
- Corrupted Download: The downloaded update files may have been corrupted during the download process due to network issues or other interruptions.
- Software Update Server Issues: Apple's software update servers might be temporarily unavailable or experiencing issues, preventing successful downloads or verification.
- Insufficient Disk Space: The system might not have enough free disk space to download and install the update.
- Corrupted Update Cache: Cached update files may be corrupted or outdated, causing the installation to fail.
- Network Connectivity Problems: A unstable or disconnected network may cause the download to fail or be interrupted causing the error.
Step-by-Step Fixes
Method 1: Restart Your Mac Show Steps ↓
Restarting your Mac can resolve temporary software glitches that may be interfering with the update process.
Step 1: Go to the Apple menu at the top-left corner of your screen.
Step 2: Select 'Restart'.
Step 3: Wait for your Mac to restart completely, then try the software update again.
Method 2: Check Your Internet Connection Show Steps ↓
Ensure you have a stable and active internet connection.
Step 1: Open a web browser and try to visit a website.
Step 2: If the website doesn't load, troubleshoot your internet connection by restarting your modem and router.
Step 3: Consider switching to a different network (e.g., Ethernet instead of Wi-Fi) to rule out Wi-Fi issues.
Method 3: Try Again Later Show Steps ↓
Apple's update servers might be experiencing high traffic. Waiting and trying the update again later can resolve the issue.
Step 1: Wait for a few hours or overnight.
Step 2: Then try to install the software update again by going to System Preferences > Software Update.
Method 4: Free Up Disk Space Show Steps ↓
Ensure you have enough free disk space for the update. Apple typically recommends having at least 20GB of free space.
Step 1: Go to the Apple menu > About This Mac > Storage.
Step 2: Review your storage usage and identify files that can be deleted or moved to an external drive.
Step 3: Delete any unnecessary files and empty the Trash.
Method 5: Delete and Redownload the Update Show Steps ↓
Remove any partially downloaded update files and attempt to download it again.
Step 1: Open Finder.
Step 2: Press Shift-Command-G to open the 'Go to Folder' dialog.
Step 3: Enter '/Library/Updates' and press Return.
Step 4: Delete the contents of the 'Updates' folder.
Step 5: Go to System Preferences > Software Update and try downloading the update again.
Method 6: Boot into Safe Mode and Update Show Steps ↓
Booting into Safe Mode prevent third-party software from interfering with the update process.
Step 1: Restart your Mac.
Step 2: Immediately after your Mac starts up, press and hold the Shift key.
Step 3: Release the Shift key when you see the login window.
Step 4: Log in to your account (you may be asked to log in twice).
Step 5: Once in Safe Mode, try updating the software through System Preferences > Software Update.
Method 7: Update via Recovery Mode Show Steps ↓
If standard methods fail, attempt the update through Recovery Mode.
Step 1: Shut down your Mac.
Step 2: Start up from macOS Recovery:
- Apple silicon: Press and hold the power button until you see the startup options window. Select the gear icon labeled Options, then click Continue.
- Intel processor: Immediately after turning on or restarting your Mac, press and hold Command (⌘)-R until you see an Apple logo or other image.
Step 3: In the Recovery Mode utilities window, choose 'Reinstall macOS'.
Step 4: Follow the on-screen instructions.