what does error code 29 indicate

Get help with iOS update and restore errors - Apple Support

Learn how to solve iOS update and restore errors.

Try these steps first

1. Get the latest version of iTunes.
2. If your device couldn't be restored and you get a message that "an unknown error occurred [error number]," use these steps. 

If you still see the error, try the steps below.

Choose your error number or message

To learn what to do, choose your error:

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