Understanding what's inside helps prevent errors during manual conversion:
Before understanding the conversion, we must understand the destination. In July 2019, Scratch 3.0 officially replaced the older .sb2 and .sb formats with .sb3 . Zip To Sb3 Converter
and all asset files (0a1b...svg, etc.) are in the root of the folder, not inside a subfolder. : Select all the files and "Compress to ZIP file." : Change the file extension from Zip To Sb3 Converter