cd scratch_project zip -r ../project.sb3 .
Some websites (including older GitHub repositories or email attachments) automatically rename .sb3 files to .zip to avoid security filters. Converting it back restores the project.
: If the project.json refers to a file name that isn't physically inside the ZIP, the project will fail to load or show "ghost" sprites.
Have questions or run into a tricky conversion? Leave a comment below or ask the Scratch community – they’re always happy to help.
will not be at the top level. When the Scratch editor opens such a file, it returns a "Project could not load" error because it cannot find the entry point. Conclusion
: Click the filename, press Enter, and change .zip to .sb3 . Confirm the change when prompted.
Here are the most common real-world scenarios: