Yeah I got the same error too but got through it by renaming DarkCastleRebuild_Harem_Data to DarkCastleRebuild_Harem_crack_Data. But this only works for harem patch exe. For some reason, there's black screen on main game. So I am stuck on that.
Original Title:俺の彼女はヒトでなし
Romaji:Ore no Tsure wa Hito de nashi
Released Date: 2010-12-24
Company, Producer: Whale
Getchu link: http://www.getchu.com/soft.phtml?id=688518