For a more reliable experience, specialized community tools can handle these conversions or packaging tasks: TurboWarp Unpackager
And from that day on, Leo never trusted a browser’s “Save as” ever again. He always, always downloaded the .sb3 directly. But he kept the hex editor close. Just in case. convert zip to sb3 fix
If you are comfortable with terminal/command prompt, this guarantees a correct conversion: For a more reliable experience, specialized community tools
To successfully convert a ZIP archive back into a functional Scratch project, follow these steps: Prepare the Content For a more reliable experience
: Select all items inside that folder, right-click, and choose Send to -> Compressed (zipped) folder (on Windows) or Compress (on macOS).