After a Switch firmware update (e.g., from 15.0.0 to 16.0.0), the encryption keys for NCA validation change. If your CFW’s prod.keys file is outdated, it may misread ProgramType.
If you know how to use PC tools like hactool , hactoolnet , or NSP Builder : the nsp file is missing a programtype nca upd
:
Use installers like Goldleaf or Tinfoil to install the base first, then the update. 3. Update System Keys and Signatures After a Switch firmware update (e
Preventive practices