FTP Error After Changing the default directory

Following are the common errors will encounter when setting anonymous vsftp
vsftpd-2.0.5error: need to access to a designated dir for anonymous ftpSet following:anon_root=/var/www/html/docs5)
error: 500 OOPS: vsftpd: refusing to run with writable anonymous rootsympton
:Reason:
Change attribute of ftp directory
from drwxrwxrwx 3 root root 4096 Jun 13 18:42 docs
To dr-xr-xr-x 3 root root 4096 Jun 13 18:42 docs
i.e;
# chmod 555 /var/www/html/docs