So...For anybody interested to know how I solved this issue without JTAC.
Go to the shell command prompt and found that the following process is responsible for web-management: /usr/sbin/httpd-gk
Than try to debug it and run manually from the shell:
root@% /usr/sbin/httpd-gk -N
dvpn_init--Entry...
smflib_open--Entry...
smflib_open--SMF connect pending
dvpn_init--sas_lic_def(0x66c594), cnt=1, name(0x66c598)=SA Client
dvpn_init--def->init() with def->lic(0x66c594), lic->cnt=1, lic->name(0x66c598)=SA Client
sas_init--Entry...lic->cnt=1, name=SA Client
sas_ike_kblob_register--Entry....
sas_init--Adding license SA Client
mv: /var/db/dynamic-vpn-ipsec/tokens-info: No such file or directory
Segmentation fault (core dumped)
That's the reason for core dump.
Create a neccesary file:
root@% touch /var/db/dynamic-vpn-ipsec/tokens-info
Run daemon again:
root@% /usr/sbin/httpd-gk -N
dvpn_init--Entry...
smflib_open--Entry...
smflib_open--SMF connect pending
dvpn_init--sas_lic_def(0x66c594), cnt=1, name(0x66c598)=SA Client
dvpn_init--def->init() with def->lic(0x66c594), lic->cnt=1, lic->name(0x66c598)=SA Client
sas_init--Entry...lic->cnt=1, name=SA Client
sas_ike_kblob_register--Entry....
sas_init--Adding license SA Client
smflib_connect--Entry...
smflib_connect--SMF connected
smflib_tx_ready--Entry...
smflib_tx--Entry...
smflib_tx--Tx_Rdy but nothing to send
Here we are, problem is solved. We may go to the configuration and activate web-management service:
root# set system services web-management https system-generated-certificate
root@% tail -f /var/log/messages
Apr 27 00:06:39 init: web-management is thrashing, not restarted
Apr 27 00:10:48 init: web-management (PID 56703) started
I'll be glad to help somebody with this solution. Topic is closed. Thanks everybody for the help.