itch.io

"November 22th"
🤣

Yeah, it sounds like you basically extracted a new installation within the existing folder. Delete that new folder and pay attention to what you're extracting and to where.
What you really want to do is select the contents of the Headmaster folder in the ZIP, and extract it to the existing main Headmaster folder (there should be game, lib, & renpy folders and four other files. These will overwrite the existing ones).

(I’d suggest renaming the Headmaster folder, just for your own reference because it's not going to be version 12.3.1 any more, but that's up to you.)

What I usually do is extract it to the existing folder and let it overwrite whatever it needs to overwrite. That seems to work fine.

So, I've played this through twice (once with a walkthrough), but I still have a gallery item locked and can't figure out how to get it. It's between "Anna2" and "Ruby3".

Well, my latest save (choice between "Let lust take over" or "Resist temptation" when looking at sister) doesn't work.
But thankfully I save often so found another recent save that worked.   👍

So, I downloaded the newest update, but I don't understand how I can use my previous saves. Every time I try to load a previous save it throws up an Exception error. Then if I say Ignore it just starts from the very beginning...