How get rid of glitch in rewrite round 2??

Everytime I press try again 1/4 of the window is black and it ends up being 1/3 of the screen if it's fullscreen. Besides this and the lag at the beginning of this song, everything else works fine. Sorry I don't have a screenshot but I don't think it was needed that much. I don't know if it's important but it's always on the very right. Does anyone know how to get rid of this?

Off topic but i LOVEEEEEE this mod omg my eyes and ears are blessed... if only i could actually beat it lol