RPG Maker Ace
Save File Doctor aims to fix the most common problem encountered when loading a save file after adding a new script to your project.
The problem is usually caused by the lack of initialization of variables used on recently added scripts. When loading an old save file, some things were already initialized and the new script will assume that’s also the case for its own variables.
It is also useful for DLC or patching systems, since it would take care of said problem in case you add scripts that way.