Hello Zumi!
So I just downloaded and extracted v13 on my phone, but when I open it (using joiplay) I get this:
this is a fatal error and I've double checked everything, including re-downloading as well as re-opening, but nothing seems to be working...
(Also, just in case you didn't know, joiplay is compatible with mkxp as I tested it with reborn.)
(Also-Also, I checked the file mentioned below, and it's there. It's not missing, and i don't know why this error keeps coming up..)