To convert a file back into a Scratch .sb3 project, you primarily need to ensure the internal structure is correct and then change the file extension. An .sb3 file is essentially a renamed ZIP archive containing your project’s assets and code. The Fast Fix: Extension Renaming
Note: Do not zip the parent folder itself; zip the files inside it. Rename the Extension Locate your new Right-click and select Change the file extension from Confirm the Change convert zip to sb3 fix
conversion is primarily a matter of archive hierarchy. By ensuring the project.json ZIP To convert a file back into a Scratch
This paper outlines the technical relationship between archives and Scratch 3.0 ( project
(Insert into existing project.json’s top-level object if missing.)
Leo frowned. He went back to his zip file. He double-clicked. Inside the zip window, he saw a folder icon named Mario_Files . He had zipped the folder , not just the files.