If one segment (like part2 ) is missing, the extraction will fail with a "Volume is missing" error.
If the file was downloaded, a single bit of corruption in Part 3 can break the entire archive. Try re-downloading that specific part. RTS0475.part3.rar
Ensure you have part1.rar , part2.rar , part3.rar , etc., in the same folder. If one segment (like part2 ) is missing,