Ftp – vsftpd: 500 OOPS: cannot change directory

Could you help me with vsftpd server. I am trying to configure it to make it work with virtual users. The problem is that I am still getting following error in ftp client:

500 OOPS: cannot change directory: [there is nothing more after : ]

Details:

# getenforce
Disabled

#ls -al /home/back
drwxrwxrwx+ 4 ftp ftp 4096 Jan 13 14:49 .
drwxr-xr-x. 5 root root 4096 Dec 23 16:10 ..
drwxrwxrwx. 2 ftp ftp 4096 Dec 3 18:00 it

#cat vsftpd.conf
anonymous_enable=YES
local_enable=YES
virtual_use_local_privs=YES
write_enable=YES
local_umask=022
dirmessage_enable=YES
xferlog_enable=YES
connect_from_port_20=NO
xferlog_std_format=YES
ascii_upload_enable=YES
ls_recurse_enable=YES
listen=YES
pam_service_name=vsftpd.virtual
userlist_enable=YES
tcp_wrappers=YES
listen_port=12121
ftp_data_port=12020
pasv_min_port=12022
pasv_max_port=12099
user_sub_token=$USER
local_root=/home/back/$USER
chroot_local_user=YES
hide_ids=YES
guest_enable=YES
allow_writeable_chroot=YES
xferlog_file=/var/log/vsftpd.log
xferlog_enable=YES
dual_log_enable=YES
port_enable=YES
pasv_enable=YES
pasv_promiscuous=YES

# cat /etc/pam.d/vsftpd.virtual

#%PAM-1.0
auth required pam_userdb.so db=/etc/vsftpd/vsftpd-virtual-user
account required pam_userdb.so db=/etc/vsftpd/vsftpd-virtual-user
session required pam_loginuid.so

Logs:

vsftpd.log (with "log_ftp_protocol=YES"):

Tue Jan 20 17:04:42 2015 [pid 13493] CONNECT: Client "127.0.0.1"
Tue Jan 20 17:04:42 2015 [pid 13492] [test] OK LOGIN: Client "127.0.0.1"
Tue Jan 20 17:06:57 2015 [pid 13584] CONNECT: Client "127.0.0.1"
Tue Jan 20 17:06:57 2015 [pid 13584] FTP response: Client "127.0.0.1", "220 (vsFTPd 3.0.2)"
Tue Jan 20 17:06:57 2015 [pid 13584] FTP command: Client "127.0.0.1", "USER test"
Tue Jan 20 17:06:57 2015 [pid 13584] [test] FTP response: Client "127.0.0.1", "331 Please specify the password."
Tue Jan 20 17:06:57 2015 [pid 13584] [test] FTP command: Client "127.0.0.1", "PASS <password>"
Tue Jan 20 17:06:57 2015 [pid 13583] [test] OK LOGIN: Client "127.0.0.1"

secure:

Jan 13 17:49:35 localhost vsftpd[10198]: pam_userdb(vsftpd.virtual:auth): user 'test' granted access

Info:

Fedora 20
3.17.7-200.fc20.x86_64 #1 SMP Wed Dec 17 03:35:33 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Do you have any idea what should I change to be able to use vsftpd server?