iTunes: Specific update-and-restore error messages and advanced troubleshooting

The device could not be restored. An internal error occurred, or Error 3200: This indicates a network-connectivity or traffic issue. If you see this error, wait an hour or more and try again.

This device is not eligible for the requested build: Also sometimes displayed as an "error 3194." If you receive this alert, update to the latest version of iTunes. Third-party security software or router security settings can also cause this issue. To resolve this, follow Troubleshooting security software issues.

Downgrading to a previous version of iOS is not supported. If you have installed software to perform unauthorized modifications to your iOS device, that software may have redirected connections to the update server (gs.apple.com) within the Hosts file. First you must uninstall the unauthorized modification software from the computer, then edit out the "gs.apple.com" redirect from the hosts file, and then restart the computer for the host file changes to take affect.  For steps to edit the Hosts file and allow iTunes to communicate with the update server, see iTunes: Troubleshooting iTunes Store on your computer, iPhone, iPad, or iPod—follow steps under the heading Blocked by configuration (Mac OS X / Windows) > Rebuild network information > The hosts file may also be blocking the iTunes Store. If you do not uninstall the unauthorized modification software prior to editing the hosts file, that software may automatically modify the hosts file again on restart. Also, using an older or modified .ipsw file can cause this issue. Try moving the current .ipsw file, or try restoring in a new user to ensure that iTunes downloads a new .ipsw.

The required resource cannot be found: This alert message occurs when your device has a newer version of iOS than what is available in iTunes. When troubleshooting a device that presents this alert message, go to Settings > General > About and check the version of iOS on the device. If it is newer than the latest released iOS version, the device may have a prerelease developer version of iOS installed. Installing an older version of iOS over a newer version is not supported.

Restore loop (being prompted to restore again after a restore successfully completes): This issue is typically caused by out-of-date or incorrectly configured third-party security software. Please follow Troubleshooting security software issues if USB troubleshooting does not resolve this issue.

There was a problem downloading the software for the iPhone (or another iOS device): See the resolution steps for error codes 3000-3999.

iTunes cannot connect to the iPhone because an invalid response received from the device: This error occurs when there are problems communicating through USB. This may be resolved by following the steps for errors 13 or 14, below.

Unknown Error containing "0xE" when restoring: To resolve this issue, follow the steps in iPhone, iPad, iPod touch: Unknown error containing '0xE' when connecting. If you have a Windows computer with an Intel® 5 series/3400 series chipset, you may need updates for your chipset drivers. See iTunes for Windows: Issues syncing iOS devices with P55 and related Intel Chipsets for more information.

Hang during restore process: Following Troubleshooting security software will frequently resolve this error. This error can be caused by the default packet size being set incorrectly. There may be third-party software installed that modifies the default packet size in Windows by inserting a TcpWindowSize or MaxGlobalTcpWindowSize entry into the Registry. Contact the manufacturer of the software that installed the packet-size modification for assistance in adjusting this TcpWindowSize values. Typically the default packet size is modified by 3G cellular network card software, ISP communication software, or Internet speed download optimization software. There are legitimate reasons to change the TCP/IP packet size and not use the Windows default settings (for example, network traffic optimization, home/broadband optimization, enterprise app optimization such as database apps, Exchange, and more). Deleting the "TcpWindowSize" or "GlobalMaxTcpWindowSize" entries in Windows Registry could affect the system's performance with other apps or on their network connections. Deleting the customized TCP/IP settings may require the reinstallation of any third-party applications that had modified the TCP/IP settings from the Windows default settings.

There are two ways to resolve this: 

You can follow this article by Microsoft: How to reset Internet Protocol (TCP/IP) , or follow the steps below to manually find and remove TcpWindowSize and MaxGlobalTcpWindowSize entries from the Registry.

Error 2: This error is frequently resolved by disabling or uninstalling third-party security or firewall software.

Error 4 (or -4): This error may occur because of one of the following conditions:

• Access to ports 80 or 443 is blocked.
• Communication to albert.apple.com or phobos.apple.com is blocked by a firewall, third-party security software, or other Internet security setting.
• The iTunes Store is experiencing extremely high traffic.
  

Error 6: All of the steps in this article apply to this issue. Following Troubleshooting security software frequently resolves this error. There may be third-party software installed that modifies your default packet size in Windows by inserting a TcpWindowSize entry into your Registry. Your default packet size being set incorrectly can cause this error. Contact the manufacturer of the software that installed the packet size modification for assistance or follow this article by Microsoft: How to reset Internet Protocol (TCP/IP).

Error 9: This error occurs when the device unexpectedly drops off the USB bus and communication stops. This can occur if the device is manually disconnected during the restore process. This issue can be resolved by performing USB isolation troubleshooting, using a different USB dock-connector cable, trying another USB port, restoring on another computer, or by eliminating conflicts from third-party security software.

Error 13 and 14: These errors are typically resolved by performing one or more of the steps listed below:

Error 18 (or -18): This occurs when the media library on the device is corrupt and cannot be modified or updated. Updating to the latest version of iTunes and then restoring should resolve this issue.

Error 19 (or -19): The full text of this error is: "iTunes could not sync to the iPhone '[iPhone name]' because an unknown error occurred (-19)". This error can occur when you attempt to update an iPhone 3G to a later version of the software and iTunes attempts to back up iPhone while it is syncing. To resolve this issue:

Error 20, 21, 34, 37: These errors typically occur when security software interferes with the restore and update process. If you are using a PC, follow this article to resolve this issue.

Error 23, 28, 29: These errors may indicate a hardware issue with your device. Follow the steps in this article. Also attempt to restore while connected with the white USB Dock Connector cable that shipped with your device, on a known good computer and network to isolate this issue to the device. The MAC address being missing or the IMEI being the default value, (00 499901 064000 0), can also confirm a hardware issue. Out-of-date or incorrectly configured security software can also cause these errors.

Error 35: You can resolve this error by using a known-good 30-pin USB Dock Connector cable. If that does not resolve the issue, follow the instructions for errors 13 or 14 above.

Error 40: This error may indicate a hardware issue with your device, but it is typically caused by out-of-date or incorrectly configured security software. Follow the steps in this article. Also attempt to restore while connected with a known-good 30-pin Dock Connector cable, computer, and network to isolate this issue to the device. The MAC address being missing or the IMEI being the default value, (00 499901 064000 0), can also confirm a hardware issue.

Error 48 (or -48): Quit iTunes and discard the .ipsw file. Then, open iTunes and attempt to download again. See the steps under the heading "Rename, move, or delete the iOS software file (.ipsw)" below for .ipsw file locations.

Error 50: This error (and error -50) are timeout errors. Follow the steps for errors 13 or 14 above.

Error 1000: If this error appears in the iPhone, iPad, or iPod updater log file, there has been an error decompressing and transferring the IPSW file that is downloaded by iTunes when restoring your device. This error is frequently caused by third-party security software interference, a poor quality Internet connection resulting in a corrupted IPSW file, or a conflict with other devices connected to your computer using USB. 

Error 1002, 1011, 1012, 1014: These errors may indicate a hardware issue with your device. Follow the steps in this article. Also attempt to restore while connected with a known-good 30-pin Dock Connector cable, computer, and network to isolate this issue to the device. The MAC address being missing or the IMEI being the default value (00 499901 064000 0) can also confirm a hardware issue.

Error 1004 and 1013: These errors may be the result of the connection to gs.apple.com being redirected or blocked. Follow these steps to resolve these errors:

1. Check security software. Ensure that communication to gs.apple.com is allowed. Follow this article for assistance with security software. iTunes for Windows: Troubleshooting security software issues.
2. Check the hosts file. The restore will fail if there is an active entry to redirect gs.apple.com. Follow iTunes: Advanced iTunes Store troubleshooting to edit the hosts file or revert to default on Windows. See section "Blocked by configuration: (Mac OS X/Windows) > Rebuild network information".
3. Try to restore from another known-good computer and network.
4. If the errors persist on another computer, the device may need service.

Error 1015: This error is typically caused by attempts to downgrade the iPhone, iPad, or iPod touch's software. This can occur when you attempt to restore using an older .ipsw file. Downgrading to a previous version is not supported. To resolve this issue, attempt to restore with the latest iPhone, iPad, or iPod touch software available from Apple. This error can also occur when an unauthorized modification of the iOS has occurred and you are now trying to restore to an authorized, default state.  Very rarely this error is caused by a hardware issue and requires service.

Error 1479: This error occurs when trying to contact Apple for an update or restore. Quit iTunes, disconnect from USB, restart the iOS device, reconnect the device to the computer, then launch iTunes and attempt to update or restore again.

Error 1600, 1601, 1602: Try the following steps to resolve this error:

Error 1603: If you receive this error and the iOS device is not automatically placed into recovery mode, it may be necessary to do so manually. Refer to iPhone and iPod touch: Unable to restore for steps on placing iPhone into forced recovery mode. Also, remove the IPSW and attempt to restore again. If you do not want to remove the IPSW in the original user, try restoring in a new administrator user.

Error 1604: This error is often related to USB timing. Try changing USB ports, uninstalling and reinstalling USB ports, and other available USB troubleshooting steps (troubleshooting USB connections, device not recognized properly, computer won't recognize a FireWire or USB device). If you are using a dock, bypass it and connect directly to the white Apple USB dock connector cable. If the issue persists on a known-good computer, the device may need service.

Error 1611: This error may indicate a hardware issue with your device. Follow the steps in this article. Also attempt to restore while connected with a known-good 30-pin Dock Connector cable, computer, and network to isolate this issue to the device. The MAC address being missing or the IMEI being the default value (00 499901 064000 0) can also confirm a hardware issue. Out-of-date or incorrectly configured proxy or security software, such as FoxyProxy, can cause error 1611. To troubleshoot third-party security software, follow these steps.

Error 1631: Insert SIM card into device and try again.

Error 1638: See resolution steps for error code 1004.

Error 1639: See this article for resolution. 

Error 2000-2009 (2001, 2002, 2005, 2006, 2009, and so on): If you experience this issue on a Mac, disconnect third-party devices, hubs, spare cables, displays, reset the SMC, and then try to restore. If you are using a Windows computer, remove all USB devices and spare cables other than your keyboard, mouse, and the device, restart the computer, and try to restore. If that does not resolve the issue, try the USB issue-resolution steps and articles listed for Error 1604 above. If the issue persists, it may be related to conflicting security software.

Errors 3000-3999 (3002, 3004, 3013, 3014, 3018, 3164, 3194, and so on): Error codes in the 3000 range generally mean that iTunes cannot contact the update server (gs.apple.com) on ports 80 or 443. This may be because out-of-date or incorrectly configured security or firewall software is interfering, an old version of iTunes is installed, an entry in your hosts file redirecting requests to gs.apple.com (see error 1004 above), or because of your Internet proxy settings. If you are using a proxy, try without using one or with a known-good network. If that does not resolve the issue, follow iTunes for Windows: Troubleshooting security software issues. Error 3014 may indicate that you need to free up more disk space on the computer before trying to restore again. Error 3194 most likely indicates you do not have the latest version of iTunes installed Update to the latest version of iTunes.  

Error 3002: If you experience this error while updating an iPod touch (2nd generation) or iPhone 3G, please use the standard update or restore process in iTunes (click Update or Restore).

Error 3004: If the steps listed in Error 3000-3999 do not resolve the issue, and you are using a Mac, you may be able to resolve an error 3004 by quitting iTunes and using the following command at the command line: dscacheutil -flushcache

Error 3194: Resolve error 3194 by updating to the latest version of iTunes. "This device is not eligible for the requested build" in the updater logs confirms this is the root of the issue. For more Error 3194 steps see: This device is not eligible for the requested build above.

Error 3200: This indicates a network-connectivity or traffic issue. If you see this error, wait an hour or more and try again.

Error 9006: Following Troubleshooting security software frequently resolves this error. There may be third-party software installed that modifies your default packet size in Windows by inserting a TcpWindowSize entry into your Registry. Your default packet size being set incorrectly can cause this error. Contact the manufacturer of the software that installed the packet size modification for assistance.

Error 9807: Verify the computer's date and time.

Error 9808 (or -9808): Follow the steps in iTunes Store: Unknown alert error message when connecting to resolve the issue. If those steps do not resolve the issue, or if the settings revert to their original values after the restart, then follow iTunes for Windows: Troubleshooting security software issues.

Error 9844: This is typically caused by incorrect firewall settings. See the section titled "Open the proper ports and allow access to Apple servers" in the Advanced Steps section below.

Error 20000-20008: This error may indicate that you have a USB communication failure due to a damaged USB 30-pin Dock Connector cable, out-of-date USB device drivers or firmware, or that other USB devices connected to your computer are interfering with iTunes communicating to the iOS device. Try restarting the PC and testing again with a different USB port. If you are using a custom Windows Theme Pack, revert to the default theme pack, restart, and try to restore.

Error 40265xxxx: Errors of the 40265xxxx range generally occur during the restore-from-a-backup phase, after iOS has been installed on the device. Restoring the device and setting up as new can resolve the issue. Before restoring as new, take steps to preserve the previous backups created by iTunes, such as copying the contents of the Backup directory onto the desktop. See iPhone and iPod touch: About backups to learn where backups are stored for your computer's operating system and additional precautionary notes regarding setting up as new. The backups created by iTunes store data such as your SMS, Favorites, Bookmarks, and other app data.

Follow these advanced steps only if the steps in TS1275 have not resolved the issue or if a specific update and restore error message recommends it. If the update or restore error message is not listed in above, try following all the steps in TS1275 and this article starting from the top down (basic to advanced steps) to resolve the issue.

Force restart your iOS device

Restore on a different computer

If another computer is not available, continue with the steps below.

Open the proper ports and allow access to Apple servers

Use MSConfig to restart your PC using Selective Startup

Stop Virtual OS environments

Restore using a new user account

Rename, move, or delete the iOS software file (.ipsw)

Restart the Apple Mobile Device Service (Windows only)

Remove and reinstall iTunes and Apple Mobile Device Support

Update or reinstall your Windows USB drivers