FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
Article Id 195387


This article helps to mitigate:
- Issues in establishing SSL VPN on Windows server.
- Issues in establishing SSL VPN on the other Windows with enabling high security level on Internet Options.

Error 'Unable to establish the VPN connection. The VPN server may be unreachable. (-14)' on FortiClient 6.2 can appear.

Error 'Unable to logon to the server. Your user name or password may not be configure properly for this connection. (-12)' on FortiClient 6.0 can appear.
On VPN Events log, there is login successfully then tunnel connection setup timeout.
Output from debug SSLVPN:
rmt_web_auth_info_parser_common:470 no session id in auth info
rmt_web_access_check:723 access failed, uri=[/remote/fortisslvpn],ret=4103,

Another Similar related warning when connecting to SSL vpn:




And Internet zone in internet options will be forced to set 'High' as security level.

In order to solve this issue, disable IE enhanced security configuration then reduce security level from 'High' to 'Medium-high' or 'Medium'.