Click in the top-left corner to open a blank sandbox. Go to the top menu bar and click File . Select Load from your computer . Choose your new .sb3 file and click Open . Option B: The Scratch Desktop App Launch the Scratch Desktop application on your computer. Click File in the upper menu. Choose Load from your computer . Locate and select your converted .sb3 project file. Troubleshooting Common Conversion Errors Symptom / Error Root Cause Actionable Solution "Could not load project" error Missing the internal project.json file.

: If Scratch fails to load the file after renaming, ensure the original ZIP contained a project.json file at its root level. If the files were inside a sub-folder within the ZIP, Scratch will not recognize them. AI responses may include mistakes. Learn more Deltarune Battle Simulator for Scratch 3DS #99 - GitHub

Check inside the original ZIP to ensure it contains code, not just images. The extension is hidden (e.g., named project.sb3.zip ).

Convert ZIP to SB3

Despite the unique name, an SB3 file is actually just a renamed ZIP archive. It contains all the internal assets needed to run your Scratch game or animation, including:

Are you getting an when trying to open the file? Did you download this file or create it yourself?

The conversion process involves renaming the file extension and ensuring the MIME type is recognized by the Scratch platform.