Hey, thanks for the translations and the tip! As you can see I don't really know what I'm doing.

I added your translations and they should work. I also made the english files match your german files in terms of file structure so hopefully that will improve compatibility.

So to be clear, the only file I changed after adding your german files was I changed localization/english/replace/game_concepts_l_english.yml. I moved that to localization/english/game_concepts_tt_l_english.yml

But what about common/game_concepts/00_game_concepts.txt? Do you know if there is there a way I can make that file more compatible?

I have updated the rar archive on my google drive link, I putted in the compatibler version, generally it doesn't matter how the files are called, it gets loaded anyway, what matters is in which folder it is, but if you name it exactly like the vanilla, it will replace the vanilla file. I changed the name just in adding in your mod name.
As you can see the file only contains the new game_concept lines, and because it isnt named the same you probably never have to update your mod again

I corrected also the gentleman and gentlewoman, but I didn't found a perfect solution, but at least it can display now

Love your mod btw, great work

It took me also long to understand the localizations
but in short, if you add new localization, it has just to be named <something>_l_<language>
and you just have to put it in the localization/<language> folder
BUT
If you wanna replace a vanilla localization line, the file with the line should be in the localization/<language>/replace folder.

Really appreciate this help. There's very little documentation as far as I can see so we have to help eachother out!

As I said in my comment, I replaced all of my code with these updates you made here.