Do not use a launch-day base NSP. You need a specific base version for the latest update to stick.
If your NSP update fails to install or causes the game to crash, common solutions include: Bug in Monster Boy and the Cursed Kingdom, can't reach 100% monster boy and the cursed kingdom nspupdate work
To ensure the update works without issues: Do not use a launch-day base NSP
| Error Symptom | Likely Cause | The Fix | | :--- | :--- | :--- | | | Missing or outdated sigpatches | Download the latest sigpatches.zip for Atmosphere. Use fusee.bin primary payload. | | Firmware requirement not met | The NSP update needs a newer Switch OS | Update your CFW firmware via Daybreak to 14.1.2 or 15.0.1. | | Already exists (Overwrite failed) | A corrupt partial update is cached | Go to Tinfoil > Tickets > Find the Monster Boy title ID > Delete all tickets. Reinstall. | | NSP is corrupted | Bad download | Re-download the update from a different source. Check the file hash. | Use fusee
For more information on Monster Boy and the Cursed Kingdom, including NSP update work, gameplay guides, and reviews, check out the following resources:
If you frequently move your files between devices, you can use a tool like to "bake" the update directly into the base game. This creates a single file that already includes all patches, so you never have to install the update separately again.