We did have some problems with a FortiClient based on a SSL VPN client. There are some stages where the clients stops and what they are.
The FortiClient stops at the next percentages of the connection:
10% – Local PC of Local Network issue;
40% – The Fortigate appliance causing a error, caused by the local machine or network setup;
45% – Problem at multifactor authentication;
80% – Username or Password issue;
98% – corruption of services. The way to resolve them is by reinstalling theClient on the laptop.
You can download the Client on the SSL VPN portal from the Fortigate of at this download link.