(if you're on windows, don't know bout anythin else) your save data is not located in the game folder, but instead in C:\Users\whatever your user id is \AppData\Local\User Data\Default\Lust Doll Plus
(if you're on windows, don't know bout anythin else) your save data is not located in the game folder, but instead in C:\Users\whatever your user id is \AppData\Local\User Data\Default\Lust Doll Plus