If you need to download older versions of the FortiClient VPN

For a system administrator managing a small business with a legacy FortiGate firewall (perhaps a 60D or 90D running firmware nearing end-of-life), the modern FortiClient is often incompatible. The new client speaks a language the old firewall no longer understands, or worse, it breaks the established tunnel protocols. Thus, the admin turns to the past, seeking version 5.6 or 6.0.6—the specific builds known for stability and standalone simplicity.

config vpn ssl settings
set tls-proto-1-0 enable
set tls-proto-1-1 enable
end

Part 5: Step-by-Step Installation of an Older FortiClient Version

Once you have safely downloaded your desired older version (e.g., FortiClientSetup_6.4.9_x64.exe), follow these steps to avoid conflicts.

Account Requirements

• Free Account: Yes, Fortinet allows you to register for a free "Support Portal" account (no active contract required). However, access to older firmware requires a contract, but older FortiClient software is generally available to registered users.
• Partner/Paid Account: If your company has a support contract, you have full access to the entire archive going back to version 5.0.