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 190758
This article describes how to establish the vpn connection when the vpn server is unreachable (-14).

While connecting SSL forticlient VPN the following error 'The vpn server may be unreachable (-14)' appears.

1) Find the picture below, there is one host and user is connected using FortiClient to establish the SSL VPN.

2) From the above image,error occurred, and this is because the credential entered was incorrect.


The same error is occured for multiple reasons, and this is one of the reason for the error.(Incorrect credentials)

3) Find the debug error below.
2020-04-18 08:31:56 local auth is done with user 'user2', ret=1
2020-04-18 08:31:56 [319:root:49]fam_auth_send_req_internal:461 fnbam_auth return: 1
2020-04-18 08:31:56 [319:root:49]fam_auth_send_req:701 clear local user flag anddo authentication again.
2020-04-18 08:31:56 [319:root:49]fam_auth_send_req:583 with server blacklist:
2020-04-18 08:31:56 [319:root:49]fam_auth_send_req:711 task finished with 5
2020-04-18 08:31:56 [319:root:49]login_failed:384 user[user2],auth_type=1 failed[sslvpn_login_unknown_user]
2020-04-18 08:31:56 [319:root:49]req: /remote/fortisslvpn
2020-04-18 08:31:56 [319:root:49]rmt_web_auth_info_parser_common:470 no session                                                                                                             
2020-04-18 08:31:56 [319:root:49]rmt_web_access_check:723 access failed, uri=[/r