when do you get the error? when you start the game or when you played to ex: an event or something?
Edit: Just in case i dont think your not doing it but anyway be sure to emulate japanese loacle whe nextracting the base game folder as fo the translation i dont think you need to i dont know my computer is set to japanese loace so i dont need to emulate it but just in case im saying it to you.
the version your useing is from dlsite and its raw and they actuly say you should run the game with your computer in Japanese Locale to prevent troubles
even when translated some games wont function correctly unless you do.
if you want to set your computers system locale this is how on windows 11 open settings click search typ in region click regions settings that comes in tab under search field scroll down to administrative language settings click to open window look for change system loacle click set to japanese (japan) and click ok you should install the japanese language pack to do this befor or after i did it befor i changed i dont know if it will promt you to install it automaticly when you change locale. and this changes nothing eccept now your computer can read japanese you will still have english or native language on your system it dosent realy change anything
after you done this delete game and unzip base game again then unzip www folder into game folder and replace and then try running the game again