Oof... Same exact error message?
I'm currently downloading the folder myself to double-check if everything's okay in there.
Unfortunately I really don't know what could be wrong at this moment. My last resort would be to attempt to launch the game using EasyRPG: https://easyrpg.org/
EasyRPG is an open-source emulator for RPG Maker 2003 games. Sometimes, it can lend a game additional stability - or so I would hope. :(
If this doesn't work either, feel free to request a refund on your purchase. I'm really sorry.