Even experienced users run into errors. Here is the troubleshooting guide.
futurerestore -t blob.shsh2 --latest-baseband --latest-sep -w iOS_15.4.1.ipsw Ecid Register Iphone
The Exclusive Chip ID, or ECID, is a 64-bit identifier stored in the Secure Enclave of your iPhone. It's a unique code that distinguishes your device from every other iPhone in the world. The ECID is used for various purposes, including: Even experienced users run into errors
Apple stops signing new versions roughly two weeks after a new release. If you just updated to iOS 17.2 and hate it, you cannot go back to 17.0 unless you for 17.0 two weeks ago. Ecid Register Iphone