No access to WebUI after upgrade

Hi!

I know that there are some posts around here telling about being able to login via SSH, working SMB, but no access to WebUI, but I have tried everything that they suggested and nothing worked.
I think that it happened after scheduled update to 2.1.6. Everything was fine until in Friday I wanted to add a user and I was unable to view OMV's page.
The thing is, that I get nothing. Tried to empty Firefox's cache, view in Private mode, logging in with IE, firstaid, reinstalling nginx, reinstalling php5, reinstalling OMV at Friday (when 2.1.6 was most up to date), reinstalling today (with 2.1.7) and nothing has changed.
Tried rm /var/cashe/openmediavault/*.json -nothing

omv-mkconf omvextrasorg aptclean - not helping

netstat -tulpen | grep 80
tcp6 0 0 :::80 :::* LISTEN 0 132126 6798/nginx
udp6 0 0 :::56341 :::* 0 7880 2019/dhclient

root@NDNS04:/etc/nginx/sites-enabled# dpkg -l | grep openmediavault
ii openmediavault 2.1.7 all Open networ k attached storage solution
ii openmediavault-keyring 0.3 all GnuPG archi ve keys of the OpenMediaVault archive
ii openmediavault-omvextrasorg 1.32 all OMV-Extras. org Package Repositories for OpenMediaVault
ii openmediavault-rsnapshot 1.0.11 all OpenMediaVa ult rsnapshot backup plugin.
ii openmediavault-snapraid 1.5 all snapraid pl ugin for OpenMediaVault.
root@NDNS04:/etc/nginx/sites-enabled# dpkg -l | grep openmediavault
ii openmediavault 2.1.7 all Open network attached storage solution
ii openmediavault-keyring 0.3 all GnuPG archive keys of the OpenMediaVault archive
ii openmediavault-omvextrasorg 1.32 all OMV-Extras.org Package Repositories for OpenMediaVault
ii openmediavault-rsnapshot 1.0.11 all OpenMediaVault rsnapshot backup plugin.
ii openmediavault-snapraid 1.5 all snapraid plugin for OpenMediaVault.

I have no idea what else I can do & I am kinda desperate.
I would appreciate some help.

I cannot see it at all. Web browsers give me massage telling that page cannot be found, or something like that. I have it set to port 80, so wrong port is not the case. I have tried to change it in omv-firstaid anyway and nothing.

monit stop omv-engined shows no error. In fact shows nothing at all, so I assume it stoped omv engine without any problem, right?

omv-engined -df gives:
Registered RPC services:
apt
certificatemgmt
config
cron
diskmgmt
emailnotification
exec
filesystemmgmt
folderbrowser
fstab
ftp
iptables
logfile
network
nfs
notification
omvextrasorg
perfstats
plugin
powermgmt
quota
raidmgmt
rrd
rsnapshot
rsync
rsyncd
services
sharemgmt
smart
smb
snapraid
snmp
ssh
syslog
system
tftp
usermgmt
webgui
zeroconf
Registered modules:
acpid
apt
certificatemgmt
collectd
cpufrequtils
cron
cronapt
email
fstab
ftp
halt
hdparm
hostname
hosts
interfaces
iptables
mdadm
monit
networking
nfs
ntp
omvextrasorg
pam
php5fpm
quota
rrdcached
rsnapshot
rsync
rsyncd
samba
smartmontools
snapraid
snmp
ssh
sysctl
syslog
tftp
timezone
webadmin
webserver
zeroconf

Also i have checked if nginx is working and it looks like it does.
ps cax | grep nginx
2868 ? Ss 0:00 nginx
2869 ? S 0:07 nginx
2870 ? S 0:07 nginx
2871 ? S 0:00 nginx
2872 ? S 0:07 nginx

Sorry for second post in a row, but I am getting some access error when I try to edit my post.

So here it is, what I wanted to add:
Can cause such a problem wrong kernel version? Maybe something in config files?

Just in case it changes anything, it runs 3.2.0-4-amd64 #1 SMP Debian 3.2.68-1+deb7u3 x86_64.
I have one more NAS running OMV and there is 3.16.0-0.bpo.4-amd64 #1 SMP Debian 3.16.7-ckt11-1+deb8u2~bpo70+1 (2015-07-22) x86_64. This one works fine on 2.1.7 (recently updated from 1.17).
I have no access to Web interface at all. Only access via SSH. SMB works fine, but I need to add one user and I am unable to do it. :-/

In first massage I wrote everything that I tried. This solution was recommended in some post here. I did quite a lot of research before starting new thread.
Did it again just to make sure and nothing.
Honestly I do not understand what is happening with this NAS.
Some people at least get "It works", or "Welcome to nginx", but here is nothing at all.
Maybe in nginx configuration something is wrong, like path to OMV's files?

EDIT: By the way, first time when I sow this command, I did look at this folder before executing it. It was empty. Is it normal? One more thing - when I try to apt-get dist-upgrade or apt-get upgrade after confirming upgrade I get "aborted" or something like that. Forgive me writing those system massages starting with "something like that", but it is translated form Polish.

OMG!!! You wil not believe it... I was connecting with TeamViewer to a computer in the network where this NAS is to access OMV's Web Interface. Never had any need to connect to any other sites despite router's wb page, switch etc. I was so focused on not working OMV's Web interface and had no need to go any other place in the network or Internet that I did not think of one more thing... It was never about OMV. I think it was working whole the time. It turned out, that fu**ing Norton Internet Security was screwing with access to web pages... Wrrrr...
Sorry 4 wasting your and my time.