Cannot use nginx plugin on Debian

Good day.
I cannot use nginx plugin in Ajenti. It shows only exclamation sign near the "Application binary".
root@none:~# aptitude show ajenti
Package: ajenti
New: yes
State: installed
Automatically installed: no
Version: 1.2.16.1
...
root@none:~# aptitude show nginx
Package: nginx
New: yes
State: installed
Automatically installed: no
Version: 1.2.1-2.2+wheezy2
Priority: optional
Section: httpd
...
root@none:~# cat /proc/version
Linux version 3.2.0-4-686-pae (debian-kernel@lists.debian.org) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Debian 3.2.51-1
...
root@none:~# cat /etc/os-release
PRETTY_NAME="Debian GNU/Linux 7 (wheezy)"
NAME="Debian GNU/Linux"
VERSION_ID="7"
VERSION="7 (wheezy)"
ID=debian
ANSI_COLOR="1;31"
HOME_URL="http://www.debian.org/"
SUPPORT_URL="http://www.debian.org/support/"
BUG_REPORT_URL="http://bugs.debian.org/"

Could you please advise how to solve this issue?
Thanx in advance.