But do you have a shell access? Can you login to that server using any SSH terminal client like PuTTY? Are you really supposed to use SCP protocol? Did you try SFTP? (
Before posting, please read how to report bug or request support effectively.
Bug reports without an attached log file are usually useless.
open scp://Unix_UserName:passUTF8HEXword@Unix.IP.Address.Number:Port -hostkey="ssh-rsa HostkeyNumber"
get -delete /UnixServerPath/File*.pdf \\WindowsServerPath\