Completed the game on normal recently and unlocked a few hoodies, pages, dev commentary and both doctor and nightmare mode. Then i went to "New Game", nightmare mode still locked.... checked the unlockables screen, everything locked... no secret room either. Then i searched the forums and tried to find similar problems through Google. So i did reset my unlockables and Loaded the Home save to Complete it again but nothing had changed. I also tried to change the compability mode to xp sp3 and started game as an Admin, nothing changes. Can't seem to figure it out. Any help?
Edit: Fixed this by uninstalling the game from Steam and then downloaded it again. Make sure everything is fresh, no old saves or nothing. Then beat the game again and it worked.