Ensure you are selecting the base game file, usually labeled with [v0] in the filename. Move updates and DLCs to a separate folder so tools like SteamRom Manager don't mistake them for the main game.
– Ensure you downloaded the base game NSP, not an update or DLC. the nsp file is missing a program type nca
Open your emulator (Yuzu or Ryujinx) first, and then manually select and launch the game from the internal list. Summary Checklist Potential Issue Recommended Action Wrong File Ensure you are selecting the base game file,