Use a tool like WinRAR or 7-Zip to extract the contents.
Resolved previous installation errors reported in V20. How to Install FPACK V21 Download File FPACK V21.rar
While "FPACK" commonly refers to the NASA FITS Image Compression Utility used in astronomy, a file named is more likely a community-created "Facepack" or "Fixpack" for a game like Football Manager or FIFA . Use a tool like WinRAR or 7-Zip to extract the contents