Technical Tip: MacOS FortiClient issue with SSL-VPN

[mkatary]

Description	There is a known behavior of MacOS Monterey FortiClient not able to connect not able to connect to FortiGate over SSL-VPN.  This article describes that this issue will appear for users using free FortiClient VPN version.
Scope	FortiGate, FortiClient.
Solution	Confirm TLS 1.3  is enabled on FortiOS. Check fortitray.log and search for the below error. 20220323 14:05:37 [FortiTray:INFO] VpnManager.swift:611 VPN connecting 20220323 14:05:37 [FortiTray:EROR] VpnManager.swift:388 Failed to get tunnel provider's return code 20220323 14:05:37 [FortiTray:INFO] VpnManager.swift:604 VPN disconnected 20220323 14:06:27 [FortiTray:INFO] VpnManager.swift:787 Start VPN: viking-river 20220323 14:06:27 [FortiTray:INFO] VpnManager.swift:611 VPN connecting 20220323 14:06:27 [FortiTray:DEBG] vpnconnection.mm:540 Server URL: https://92.43.224.11:10443 20220323 14:06:28 [FortiTray:INFO] VpnManager.swift:1397 Input request type: USER_INPUT_REQUEST_INVALID_CERTIFICATE 20220323 14:06:28 [FortiTray:INFO] sslvpn.cpp:215 ApiEncMethod: 0 20220323 14:06:28 [FortiTray:INFO] sslvpn.cpp:217 ApiRemoteAuthTimeout: 30 20220323 14:06:28 [FortiTray:INFO] sslvpn.cpp:219 ApiServerSalt: 3414a8b1 20220323 14:06:28 [FortiTray:INFO] sslvpn.cpp:220 flag: 223 20220323 14:06:28 [FortiTray:INFO] sslvpn.cpp:314 Send authentication request 20220323 14:06:28 [FortiTray:INFO] sslvpn.cpp:506 Authentication passed 20220323 14:06:29 [FortiTray:DEBG] vpnconnection.mm:400 Stop process. 20220323 14:06:29 [FortiTray:INFO] VpnManager.swift:1475 Notification: Cancel input 20220323 14:06:29 [FortiTray:INFO] sslvpn_bridge.mm:71 Login successful 20220323 14:06:29 [FortiTray:INFO] sslvpn.cpp:575 Login successful 20220323 14:06:29 [FortiTray:INFO] VpnManager.swift:1183 Inherit proxy settings 20220323 14:06:29 [FortiTray:INFO] VpnManager.swift:1217 Setup proxy exceptions 20220323 14:06:31 [FortiTray:DEBG] AppDelegate.swift:151 Reload config 20220323 14:06:31 [FortiTray:EROR] ConfigManager.swift:1522 Config file "/Library/Application Support/Fortinet/FortiClient/conf/epctrl.plist" not exist 20220323 14:06:31 [FortiTray:INFO] VpnManager.swift:611 VPN connecting 20220323 14:06:31 [FortiTray:EROR] VpnManager.swift:388 Failed to get tunnel provider's return code 20220323 14:06:31 [FortiTray:INFO] VpnManager.swift:604 VPN disconnected Use the FortiClient version 6.4.6 (download from infosite). FortiClientVPN_6.4.6.1378_OnlineInstaller.dmg