: Right-click on the first file in the sequence ( 521_3_RP.part1.rar ).
: Check that all parts follow the same naming convention (e.g., 521_3_RP.part1.rar , 521_3_RP.part2.rar ). If any were renamed during download, they must be renamed back to match the sequence. 521_3_RP.part2.rar
How to extract multipart rar with missing parts? - Super User : Right-click on the first file in the sequence ( 521_3_RP
: Ensure every part of the sequence is downloaded and located in the same directory. 521_3_RP.part2.rar