Are you accidentally renaming or missing the fonts so you've renamed the files? A good half the file names are using Katakana/Hiragana. You can usually tell by looking into the given folder (the hieroglyphs2.png won't be there, but rpgmvp files are, and you should be able to tell if it is messed up).
My expectation is it'll be found in one of the 近衛騎士.rpgmvp files, and if one of those is renamed it'll be unable to find the .png as well.
I downloaded and started a fresh file the pixeldrain link, so it isn't the file. (I've no interest in replaying, but I passed the area you had an issue with.)