Use a tool like WinRAR or 7-Zip to extract the .nsp file from the .rar archive.
Move the extracted .nsp file to your Switch's SD card. Undertale-NSP-UPDATE-ROMSLAB.rar
This archive contains the latest update for on the Nintendo Switch. This update ensures compatibility with the latest system firmware and addresses various bug fixes and performance improvements to provide the best underground experience. Installation Instructions Use a tool like WinRAR or 7-Zip to extract the
Use your preferred title manager (such as Tinfoil, DBI, or Goldleaf) to install the update. Undertale-NSP-UPDATE-ROMSLAB.rar
Ensure your custom firmware (CFW) is up to date to avoid installation errors. Always back up your save data before applying updates.
Once installation is complete, launch the game from the home menu. Notes Requires the base game installed to function.