Error 9006 is one of the most common iTunes errors that occurs when updating or restoring iOS device firmware. Correcting it is not so difficult.
Typically, iTunes update Error 9006 is accompanied by a message stating that there was a problem downloading the update for iPhone or iPad. Sometimes the iTunes download Error is simply aborts with the message err = 9006.
Error 9006 occurs due to an unsuccessful attempt to connect to the Apple update servers, which, in turn, is caused by a broken download.
Read more: How to Fix Error 3194 from iTunes During iPhone Restore?
Fix iTunes Error 9006
Most often, the antivirus or firewall is to blame for all this, however, sometimes the problem can be related to the Internet connection, a specific computer, version of iTunes or the OS. To fix error 9006, you need to do the following steps:
- Check the network connection and make sure that you are connected to the Internet;
- Completely quit or force quit iTunes;

- Check and install iTunes updates and any macOS or Windows updates, if available;

- Restart a computer;

- Disable any antivirus software and firewalls for a term of iTunes usage;
- Try plugging your iOS device into another USB port or trying to use another cable.

Conclusion
In most often cases, disabling third-party firewalls and antiviruses during the update helps to avoid errors.
If this does not help, then most likely the problem is either in the Internet connection itself, which may have limitations that do not allow you to contact Apple servers, or in the computer due to changed settings in the hosts file that block access to the update servers. In this case, it is worth trying to upgrade by connecting to another network, or use another computer.
In the most sad case, it is worth contacting Apple support to restore your iPhone or iPad.
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