I have just help a customer, with a problem with his FortiClient.
The Forticlient did connect successful, and everything looks good, but there are no traffic iis recieved.
The OS of the customer where Windows 11.
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The solutions where quite simple, just uninstall this microsoft update: KB2693643
Read more about the error here: https://community.fortinet.com/t5/FortiClient/Troubleshooting-Tip-VPN-SSL-connected-but-no-IP-address-in/ta-p/248143