To resolve this during a custom installation or bypass process, you must manually register your device's ID with the service you are using: Secure software updates - Apple Support (KZ)

Network and hosts file

: Some tools like Broque Ramdisk allow you to copy the ECID directly from the interface while the device is in recovery mode. 2. Register the ECID

By following the methods above, you can resolve the error in under 10 minutes and get back to restoring your device successfully. When in doubt, put your device into DFU mode and restore to the latest official iOS—that will never trigger an ECID error.

If you are encountering this while using a specific software tool: Locate Your ECID Connect your device to a computer.