@scinkx DLC 5 was developed for Xbox, which uses custom Fast Files. They are data containers that store game assets like maps, textures, scripts, sounds, etc. These specific FF files rely on a completely different architecture, with compression, endianness and formats designed specifically for Xbox. In short, they are not compatible with the PC version. Many developers are aware of DLC 5, but nobody currently has the time to attempt a port, and it’s not going to be easy