Get help with iOS update and restore errors

Learn how to solve specific iOS update and restore errors.

Use these basic steps when you see this message: "The iPhone [device name] could not be restored. An unknown error occurred [error number]." If you still see the error message, find your error below to learn what to do.

Choose your error number or message

Select your error to learn what to do:

Check for communication issues

If you see error 1671, iTunes is downloading necessary software. Wait for the download to finish and try again. To see how long the download should take, you can click the down arrow in the upper-right corner of iTunes. Update to iTunes 12.5.4 or later to fix error 1671.

If you see one of the issues below, your computer might not be able to connect to Apple servers or your iPhone, iPad, or iPod touch:

  • 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."

Check for communication issues between iTunes and Apple software-update servers. Also check for issues with third-party security software.

If you still see an error message, contact Apple Support.

Check your security software

Check your USB connections

If you see error 4005, 4013, or 4014, learn what to do. If you see one of the errors below, you might have a USB connection issue:

  • 13, 14, 1600, 1601, 1602, 1603, 1604, 1611, 1643-1650
  • 2000, 2001, 2002, 2005, 2006, 2009
  • An error message that includes, "invalid response"

Use these steps to see if the issue is with your USB cable, USB port, or computer. Try again after each step:

  1. Use the USB cable that came with your device. If you don't have it, try a different Apple USB cable. 
  2. Switch to a different USB port on your computer. Don't plug into your keyboard.
  3. Plug into a different computer.
  4. If you still see the error, you can check for other USB issues, issues with third-party security software, and issues with hardware.

If the issue continues, contact Apple Support.

Check for hardware issues

If you see error 53, learn what to do. If you see one of the errors below, you might have a hardware issue:

  • 1, 3, 10, 11, 12, 13, 14, 16
  • 20, 21, 23, 26, 27, 28, 29, 34, 35, 36, 37, 40, 56
  • 1002, 1004, 1011, 1012, 1014, 1667 1669

Here's what to check:

  1. If iTunes is already open, quit and reopen it.
  2. Make sure that you have the latest version of iTunes.
  3. Check for issues with third-party security software.
  4. Make sure that your USB cable, computer, and network are reliable. Then try twice more to restore your iPhone, iPad, or iPod.
  5. If you still see the error message, you can check for outdated or modified software or contact Apple Support.

Check for outdated or modified software

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

Update to the latest version of iTunes, then use recovery mode to restore your device to the latest version of iOS.

If you still see an error message, contact Apple Support.

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