I use the standalone one on here so I think it's count as fresh one, I think? and i didn't download the tweak patch, so I don't think it's tweaked.
I found the bug on the saved one first (I use story mode here), and then I tried on new game (with sandbox mode) and still it show same error.
later on , I found out that it affect the slave merchant too (the one that met for melisa(?) youthful potion quest). I could still open his item shop and sell slaves options, but when I sell a slave, they didn't get removed but I'm still get the money from selling them.
aaand...idk but, I see there's some file with "_ALT" on the file name and as far as I learned, it should be a replacer for the original file? (welp, I saw some post somewhere said something about that). I haven't try to change them because I don't want to get more error for now.