This specific file is a of a FitGirl Repack. Repackers often separate non-essential data—like high-resolution textures or different language packs—into optional files.
To ensure your game installs correctly with German language support, follow these steps: setup-fitgirl-selective-german.bin.part3.rar
: This indicates that the file contains the German language data (voiceovers, localized text, or UI) for the game. This specific file is a of a FitGirl Repack