oh my ALLAH it is solve see the content of proftpd.group i copy line 1 and change it to soroushir:*:1010: now it works dear falko...
no , soroushir is not in /etc/passwd i create a user name=ftpbackup uid=1010 /etc/passwd has this line ftpbackup:*:1010:1010:User...
i install proftpd ./configure make && makeinstall then create user for it my proftpd.conf ServerType standalone...
Separate names with a comma.