Your base NSP, the Update file, and the DLC files must all share the same Title ID.
This usually happens if the Update version is higher than what your System Firmware supports. gearclub unlimited 2 switch nsp update dlc work
: Without the latest sigpatches, the Switch will display "the software was closed because an error occurred" or "unplayable content" when attempting to launch a game with DLC/Updates. Version Matching Your base NSP, the Update file, and the
If you’re asking whether a (e.g., from “non-eShop” sources) works with updates and DLC on a modded Switch (Atmosphere, SX OS, etc.): Your base NSP