Never mind, apparently rUGP just works so stupidly that it doesn't like any non-Latin characters or non-Japanese characters in the file path... So no commas and the such... Wow.
I've run into a problem when I try to run the game executable (I use Windows 10 Japanese locale), rUGP just throws me this error code. It tells me to start in Safe Mode, and offers to when you press [Yes]. I've pressed [Yes] and it's done nothing, and when I try to run the executable again, it...