Q: error message when connecting

Try the following steps:

1. Make sure you have the latest version of iTunes. Get the Latest Version of iTunes - Apple Support
2. Restart both your iPod and computer.
3. If that doesn’t work, contact Apple Support.
4. Also take a look at this discussion thread for more information: https://discussions.apple.com/thread/7296770

Good luck!

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.

from:

Get help with iOS update and restore errors - Apple Support