iOS update and restore errors

Learn how to solve iOS update and restore errors.

Try these steps first

1. Install software updates:

   • macOS Catalina 10.15 or later

   • macOS Mojave 10.14 or earlier

   • PC

2. If your device didn't restore and you get the "An unknown error occurred [error number]." message, use these steps.

If you still see the error, you may need to troubleshoot further.

Choose your error number or message

Update the software on your Mac or PC

Error 10 means that your iOS device's software is too new for your Mac or PC. Update your Mac's software, iTunes, or the Apple Devices app on Windows:

1. Disconnect and then reconnect your iOS device to your computer.

2. If your Mac doesn't recognize your iOS device, unlock it.

3. If you need the software update, click Install.

Check that your device can connect to Apple servers

If you see Error 1671, wait for your computer to finish downloading software, then try again.

If you see these errors, your computer can't connect to Apple servers or your device:

• 17, 1638, 3014, 3194, 3000, 3002, 3004, 3013, 3014, 3015, 3194, 3200

• "There was a problem downloading the software."

• "The device isn't eligible for the requested build."

Here's what to check:

1. Check that your computer can connect to Apple's software update servers.

2. Check that your third-party security software isn't blocking connections.

If you see Error 4037, unlock your device first. Your computer can't update a locked device.

Learn what to do if you forgot your passcode.

Fix Cellular Update Failed or Apple Pay Not Available alerts

If you see either "Cellular Update Failed" or "Apple Pay requires an Update on this iPhone" alert after an update:

1. Open the Settings app.

2. Tap the message to learn more about it.

3. Make sure that you have a backup of your iPhone or iPad.

4. Connect your device to a computer that has the latest version of macOS, iTunes, or the Apple Devices app.

5. If "Trust this Computer" appears, unlock your device, then tap Trust.

6. Select your device.

7. In the Finder or Apple Devices app, click General. Or in iTunes, click Summary. Then:

   1. On a Mac: Command-click Check for Update.

   2. On a Windows computer: Control-click Check for Update.

8. Click Download and Update.

9. Follow the onscreen instructions.

Your computer downloads and installs the current version of software on your device. Don't disconnect your device from your computer until the download completes.

Check your security software

• If you see Error 9, try to update your device again.

• If you see error 2, 4, 6, or 1611, check your third-party security software, then check your USB connection.

Check your USB connections

If you see error 4005, 4013, or 4014, try to update your device again.

If you see one of these errors, check your USB connection, USB cable, USB port, or computer:

• 13, 1600, 1601, 1602, 1603, 1604, 1611, 1643–1650

• 2000, 2001, 2002, 2005, 2006, 2009

• An error that includes "invalid response"

Here's what to check. Try again after each step:

1. Use the USB cable that came with your device. If you don't have it, use another Apple-certified USB cable.

2. Switch to a different USB port on your computer. Don't use the USB port on your keyboard, as keyboards often lack sufficient power for updating or restoring devices.

3. Switch to a USB port on a different computer.

4. If you still see the error, check for other USB issues, check your third-party security software, then check your hardware.

Check your hardware

Learn what to do if you see Error 53.

If you see one of these errors, you might have a hardware issue:

• 1, 3, 11, 12, 13, or 16

• 20, 21, 23, 26, 27, 28, 29, 34, 35, 36, 37, 40, or 56

• 1002, 1004, 1011, 1012, 1014, 1667, or 1669

Here's what to check. Try again after each step:

1. If iTunes is already open, quit and reopen it.

2. Check your third-party security software.

3. Make sure that your USB cable, computer, and network are reliable.

4. Try again to restore your device.

5. Check for outdated or modified software.

Check for outdated or modified software

If you see Error 1015 or a message that "The required resource can't be found," your device might have unauthorized software modifications (jailbreaking). Or you might be trying to install an earlier version of iOS (downgrading).

To restore your device to the latest version of software, you might need to use recovery mode on your iPhone or recovery mode on your iPad.