Ecid Not Registered Install _hot_ (Limited – PICK)

If you are a registered developer trying to install a beta:

For the vast majority of users, the solution is to stop fighting the IPSW file and check your beta enrollment status, or accept that the software version you are trying to install is no longer supported by Apple's servers. The fingerprint of your device is valid; it is simply the paperwork for the installation that is out of date. ecid not registered install