Unable to establish the vpn connection. The vpn server may be unreachable - FortiClient Error

Please follow the below instruction to resolve the above error.

• Please check the "TLS 1.1 and TLS 1.2" is disabled in the Internet explorer settings.
• Go to Internet Explorer an click on the setting. 

• Select "Internet Options" and go to "Advance" tab.

• If you are using the old FortiClent versions can getting the above error. Therefor please upgrade to the new version.
• Make sure you have the internet connection. The 80% of this issue getting by not having the internet connection.
• If the above options are not working, please contact your IT Help-desk to check the server issues as a hit the traffic at the moment or a any downtime at the server.