Ensure Campsitepack1.part1.rar , Campsitepack1.part2.rar , and any other numbered parts are in the same folder .
You can't usually extract part2 by itself; the data is "stitched" across all parts. To open it, follow these steps: Campsitepack1.part2.rar
If you try to extract and get an error saying "Volume is missing," it means you’re likely missing part1 or part3 . Why "Campsite Pack"? Ensure Campsitepack1