When you update or restore your iPhone, iPad, or iPod touch in iTunes, you might see this message: "The iPhone [device name] could not be restored. An unknown error occurred [error number]."
Before you try the steps below, go through the basic steps to resolve iOS update and restore errors in iTunes.
Find your error number
If you tried the basic steps and still see the error message, click your error number and follow the advanced steps below.
Solve network errors
Errors: 17, 1638, 3014, 3194, 3000, 3002, 3004, 3013, 3014, 3015, 3194, 3200. You might also see these alert messages:
- "There was a problem downloading the software."
- "The device isn't eligible for the requested build."
These alerts mean that your computer is either having difficulty contacting the Apple update server or communicating with your device.
Check your computer for software or settings that might cause communication issues between your computer and Apple or between your computer and your device.
If you still see the error message, check your security software.
Check your security software
Errors: 2, 4, 6, 9, 1611, 9006.
Sometimes security software can stop your device from communicating with either the Apple update server or with your device.
Check your security software and settings to make sure that they aren't blocking a connection to the Apple servers.
If you still see the error message, check for USB connection issues.
Check your USB connections
Errors: 13, 14, 1600, 1601, 1602, 1603, 1604, 1611, 1643-1650, 2000, 2001, 2002, 2005, 2006, 2009, 4005, 4013, 4014. You might also see a message that includes "invalid response."
If the USB connection between your device and computer is interrupted, you might not be able to update or restore.
To narrow down the issue, try different equipment:
- Use the USB cable that came with your device, or a different Apple USB cable.
- Plug your cable into a different USB port directly on your computer. Don't plug it into your keyboard.
- Try a different computer.
- Solve other issues with the USB connection, then with your security software.
If you still see the error message, check for hardware issues.
Check for hardware issues
Errors: 1, 3, 11, 12, 13, 14, 16, 20, 21, 23, 26, 27, 28, 29, 34, 35, 36, 37, 40, 53, 1002, 1004, 1011, 1012, 1014, 1667, or 1669.
Your device or computer might have a hardware issue that stops the update or restore from completing.
- Check that your security software and settings aren't blocking your device from communicating with the Apple update server.
- Then try to restore your iOS device two more times while connected with a cable, computer, and network you know are good.
- Make sure that your security software and settings are allowing communication between your device and update servers.
- If you still see the error message when you update or restore, contact Apple support.
If you still see the error message, check for outdated or modified software.
Check for outdated or modified software
s: 1015. You might also see the message "The required resource can't be found."
These errors might appear if any of the situations below are true:
- Your version of iTunes is out of date. Get the latest version of iTunes, then try to update or restore again.
- Your device has a beta version of iOS.
- You're trying to install an earlier version of iOS (downgrading).
- Your device has unauthorized modifications to iOS, also called "jailbreaking."
Use recovery mode to restore your device to the latest version of iOS.