After have  installed ProFTPD latest version and configured in on your machine, if you may get an error while restart the ProFTPD service,  ProFTPD Unable to Use World Readable AuthUserFile. 



2016-05-19 07:28:46,408 ip-172-30-1-16 proftpd[5653]: mod_auth_file/1.0: unable to use world-readable AuthUserFile '/etc/proftpd/passwd.vhost' (perms 0777): Operation not permitted

2016-05-19 07:28:46,408 ip-172-30-1-16 proftpd[5653]: fatal: AuthUserFile: unable to use /etc/proftpd/passwd.vhost: Operation not permitted on line 40 of '/usr/etc/proftpd.conf'


Simply remove all permissions except of owner (0600) for passwd files "/etc/proftpd/passwd.vhost" and restart ProFTPD.



# chmod 0600 /etc/proftpd/passwd.vhost



# service proftpd restart