Proftp : Unknown configuration directive ‘VRootEngine’

Error :
proftpd[3321]: Fatal: Unknown configuration directive ‘VRootEngine’ on line 16 of ‘/etc/proftpd.conf’

Solution :
Edit /et/proftpd.conf file.

...
VRootEngine                     on
DefaultRoot                     ~ !adm
VRootAlias                      /etc/security/pam_env.conf etc/security/pam_env.conf
...

Change to

...
<IfModule mod_vroot.c>
VRootEngine                     on
DefaultRoot                     ~ !adm
VRootAlias                      /etc/security/pam_env.conf etc/security/pam_env.conf
</IfModule>
...

# service proftpd start
# nestat an | grep 21