- Part 1: Cancel and Re-download macOS Sierra 10.12.1 Update Pack
- Part 2: Check System Status Page When macOS Sierra 10.12.1 Update Freezes
- Part 3: Free Up Enough Storage Space for macOS Sierra 10.12.1 Update
- Part 4: Update macOS Sierra 10.12.1 in Safe Mode When It Fails
- Part 5: Remove Outdated Wi-Fi Preferences If macOS Sierra 10.12.1 Won’t Update
- Part 6: Safe Way to Recover Lost Data after macOS Sierra 10.12.1 Update

Recover the lost/deleted data from computer, hard drive, flash drive, memory card, digital camera and more.
Fix macOS Sierra 10.12.1 Update Stuck Error without Data Loss

Do you receive the message An error has occurred not found (10403) or An error has occurred forbidden (104030) while updating to macOS Sierra 10.12.1? What can you do when the Apple update error 10403 pops up?

Actually, Apple update not found 10403 is one of the frequently-asked Mac installation errors. You can take measures to fix macOS Sierra 10.12.1update stuck error with the following solutions.
By the way, you can protect Mac files from data loss because of macOS Sierra installing or updating stuck errors.
Guide List
- Part 1: Cancel and Re-download macOS Sierra 10.12.1 Update Pack
- Part 2: Check System Status Page When macOS Sierra 10.12.1 Update Freezes
- Part 3: Free Up Enough Storage Space for macOS Sierra 10.12.1 Update
- Part 4: Update macOS Sierra 10.12.1 in Safe Mode When It Fails
- Part 5: Remove Outdated Wi-Fi Preferences If macOS Sierra 10.12.1 Won’t Update
- Part 6: Safe Way to Recover Lost Data after macOS Sierra 10.12.1 Update
1. Cancel and Re-download macOS Sierra 10.12.1 Update Pack
Step 1Find the software you are downloading. Hold and press Option and Alt keys. Click the Cancel option to cancel a Mac update in progress.
Step 2Visit the Mac App Store or the Apple Support site. Search the macOS Sierra 10.12.1 update.
Step 3Download and install the macOS update again.

2. Check System Status Page When macOS Sierra 10.12.1 Update Freezes
Step 1Visit https://www.apple.com/uk/support/systemstatus/ to access Apple System Status page.
Step 2Find macOS Software Update in the list.
Step 3Check the icon’s color. If the icon is green, it means the macOS Sierra 10.12.1 update error is not caused by Apple’s server.

3. Free Up Enough Storage Space for macOS Sierra 10.12.1 Update
The Mac installation error can be caused by the shortage of startup disk storage space too. In another word, you need to leave enough storage space to fix macOS Sierra 10.12.1 update stuck error. You can delete some large files manually, like previous downloaded movies, inactive software and more.
By the way, you can use Mac cleaning software to delete junk files completely.
Make sure there is at least 2GB memory and 8.8GB storage space. Moreover, you need to leave more than 50% battery on your Mac computer. It would be better if you plug Mac into a power source.
Otherwise, your Mac may freeze during the macOS Sierra 10.12.1 update.

4. Update macOS Sierra 10.12.1 in Safe Mode When It Fails
Step 1Long press Power to shut down your Mac computer.
Step 2Power on Mac while holding the Shift key on your keyboard.
Step 3Release Shift when you see the Apple logo on the Mac screen.
Step 4Sign into your account in the login window.
Step 5Reinstall macOS Sierra 10.12.1 update in Safe mode to fix Mac OS update failed errors.
Note: The minimum storage space requirement is 9GB for booting Mac in Safe Mode.

5. Remove Outdated Wi-Fi Preferences If macOS Sierra 10.12.1 Won’t Update
Step 1Click any empty space on the desktop. Hold and press Command, Shift and G keys simultaneously.
Step 2Type /Library/Preferences/SystemConfiguration/ in the “Go to Folder” window. Then press Enter to go ahead.
Step 3Search and deleted those files
com.apple.airport.preferences.plist
com.apple.network.identification.plist
com.apple.wifi.message-tracer.plist
NetworkInterfaces.plist
preferences.plist
Step 4Reboot Mac and restart the Wi-Fi router to fix macOS Sierra 10.12.1 update stuck or fail to download error.

If you delete the data accidentally, you can also use FoneLab Data Retriever as a Recycle Bin Data Recovery to get the lost data back with ease.
6. Safe Way to Recover Lost Data after macOS Sierra 10.12.1 Update
Data Loss always comes with Mac update stuck errors. During this time, you can run FoneLab Data Retriever to recover deleted or lost Mac files without backup. The powerful Mac data recovery software can help you get back videos, music, documents, emails and many other files due to macOS Sierra 10.12.1 update failures. And it also can be your hard drive data recovery, hard drive partition data recovery and more.
Compared with the traditional Time Machine backup and restore method, you can get more customizable filters to scan and recover lost data on Mac. To be more specific, you can recover lost data after macOS Sierra update without overwritten safely and quickly.

FoneLab Data Retriever - recover the lost/deleted data from computer, hard drive, flash drive, memory card, digital camera and more.
- Recover photos, videos, contacts, WhatsApp, and more data with ease.
- Preview data before recovery.
So calm down when you cannot find important documents, you can turn to FoneLab Data Retriever for help.
- Recover deleted or lost images, audios, videos, emails, documents and other files in various formats.
- Recover lost and existing data due to deletion, update stuck, formatted partition, RAW hard drive and other data loss errors.
- You can recover data from Windows, Mac, memory cards, flash drive, hard drive, digital camera camcorder, etc.
- Offer Quick Scan and Deep Scan modes to find your file effectively.
- Available for Mac 10.7 and above versions (macOS Mojave included).

These are all workable methods to fix macOS Sierra 10.12.1 update stuck error. Remember to have a copy of important Mac files before updating. If you forgot to make a backup, you can also run FoneLab Data Retriever to recover any Mac data with ease.
You can also learn more about how to fix Macbook Pro shuts down randomly, recover Mac data external hard drive read-only, USB flash drive not showing up on Mac and more easily and effectively.