7-Zip 9.20 supports RAR 2/3/4 formats only and doesn't support RAR5 archives. But latest versions of 7-Zip supports RAR5 archives.
The user likely intended to find: http://www.51scopeon.com/files/setup.rar or a similar valid URL. However, as of this writing, 51scopeon is not a well-known, mainstream domain. This raises immediate red flags. http www51scopeon files setuprar
Given the unusual domain 51scopeon.com , it is that this is either a low-traffic private site or a potentially unsafe download portal. 7-Zip 9