Are you trying to install these on the or Epic Games Store version?
The "part4" designation indicates this is one piece of a multi-part compressed archive. To access the content, you generally need all parts (part1, part2, etc.) in the same folder. FUSER.ALL.DLC.part4.rar
Songs by artists like Dua Lipa, The Killers, and Billie Eilish. Are you trying to install these on the
These archives typically aim to complete the setlist, which originally featured: you generally need all parts (part1