oh hmm, i don't know anything about itch launcher stuff, maybe it has a problem with rpg maker games in general? is there a way to find the game folder on your computer and open it from that??
Yes, and I tried to run that, too, without success. It's showing me the same error message.
Update: Solved the problem! I had to install the RTP for RPG Maker VX Ace. After a restart, everything worked fine.