Immutable
release. Only release title and notes can be modified.
A bit over a month ago, Scratch released a new version of the code editor. You may have heard of it under the name "spork". It has a few backwards incompatibilities with old versions of Scratch, and some corruption bugs resulting in invalid project.json. We've taught sb3fix to make projects backwards compatible again and to recover some of the corruption issues enough that the project can still load.