MYA use relative path so you have to execute with java from the folder containing the .jar files (which also contains data
folder).
First, change working directory:
D:
cd D:\Itch.io\Files\Apps\make-your-adventure
Then open with java:
java -jar Juego.jar
Same steps for Creacion.jar
If you have no luck send me the log.
Thanks for this useful information! We will make it easier to run the game and the editor to avoid these problems.