Hello there I just now saw you edited your post so I want to clarify things.
I am 99% sure it is directly connected to changing the unicode settings to japanese and back (though I have to admit I have 0 coding experience). The Game will not work consistently when the unicode regional setting is set to Japan (same with a lot of Japanese based games when the unicode is set to anything other than that which is the reason why i stumbled upon this problem) and give the mentioned .dll error with the suggestion to check for viruses.
In my coding ignorance i just assume it has to do with how also the filepaths change since there is no \ on the japanese keyboard (not that i know of) and the file adresses use another sign for that.
Still ejoying the game btw. keep up the good work.