The error message “ECID not registered install” typically appears when attempting to restore or downgrade an iOS device (iPhone, iPad, iPod touch) using custom firmware or a saved SHSH blob, particularly with tools like iFaith, Redsn0w, or Odysseus. It indicates that the device’s Exclusive Chip ID (ECID) is not recognized by Apple’s signing server for the requested firmware version, or that the required authentication data is missing locally.
Server Authentication: Many bypass or jailbreak tools require your ECID to be whitelisted in their private database to prevent unauthorized use. ecid not registered install
Conclusion
Network and hosts file