Delete the file named rep_persistentgamedata1.dat in this directory as well. Paste a second copy of your downloaded 100% save file here.
C:\Users\[YourUserName]\Documents\My Games\Binding of Isaac Repentance\ binding of isaac repentance 100 save file install
You missed turning off Steam Cloud before pasting the files, or you selected "Cloud Files" when turning it back on. Delete the files, turn off Steam Cloud, paste the new save, launch the game, close it, and then re-enable Cloud sync. Game Crashes on Launch Delete the file named rep_persistentgamedata1