It should work. Try to put it in the Translations folder, it should show up in the game if it works.
Viewing post in Ero Dungeons [Old Version] comments
Hi, I just noticed the german translation is partial only, so it seems I'll have to restart from a complete one, like the korean, as I can't be sure if I'm missing entries. It will take a bit more time than expected.
Also, it indeed shows up in game if put in folder, but language doesn't change even if selected. Anyway, when it's finished I'll send it to you, you'll know what to do with it.
Thanks!