Fail to login FortiClient VPN on iOS 15 device

[roy123456]

Hi,
My Apple device running iOS 15.6.1 is failing to connect to FortiClient VPN. In Android and Windows OS, the FortiClient VPN connection is normal.

IOS 15.6.1 ( FortiClient 7.4.2.0151) – Not work * No popup for enter the username and password

IOS 18.1 ( FortiClient 7.4.2.0151) - OK

Does anyone know if there is any compatibility issue between FortiClient 7.4.2.0151 and devices running iOS 15.6.1? 

Remark: The related FortiGate firewall is running v7.2.5.

[sjoshi]

Hi roy123456,

PuTTY SSH1:
------------

get vpn ssl monitor
diagnose vpn ssl list
diagnose firewall auth list
dia vpn ssl statistics
exec vpn sslvpn list
get system status
diag vpn ssl stat

PuTTY SSH2:
------------

diag sys flash list
diag debug reset
diagnose debug console timestamp en
diagnose vpn ssl debug-filter src-addr4 x.x.x.x - Here x.x.x.x is the public IP of the user connecting.
diag debug appl sslvpn -1
diag debug appl fn -1
diag debug enable

wait till the VPN disconnect, disable the logs by executing

diag debug disable
diag debug reset

[roy123456]

Hi sjoshi,

Please note that there are no popup page for enter username and password when I try to connect the VPN in FortiClient.
When click the “VPN” button, a popup page will show as attached. Then I click the “OK” or “cancel”, it will return to the startup page. 

Since the I cannot enter the username and password, I believe the VPN connection is not being established between the end device and the firewall at that moment, so the firewall log capture may not provide any useful information.

I found that someone has a similar symptom when connecting to the VPN with an iOS 15 device, but there is no solution for this issue.

https://community.fortinet.com/t5/Support-Forum/Forticlient-7-4-0142-will-not-display-login-screen-o...

Do you have any suggestions to resolve this issue?

Thank you.