Players who already own Have A Nice Death on the Nintendo Switch can update to the latest version by following these steps:
Your sigpatches are outdated. Update your Atmosphere and fusee.bin to the latest version (at least Atmosphere 1.5.0). Have A Nice Death Switch NSP -Update- -eShop-
Corrupted download. The update file must match the region of your base NSP. Do not mix a US base with a EUR update. Players who already own Have A Nice Death