Forticlient problem with ssl vpn block 10% error "vpn server may be unreachable"

Hello.

I have an issue with the forticlient and vpn ssl

I have several computers wich must connect by ssl vpn using the forticlient.

Some of the computers are working. The ssl vpn is establishing correct and i can access to the lan.

The computers working run windows 10, windows 7.

They run v 6.4, 6.2, 5.9 of the forticlient.

But some computers are not working.

They stop at 10% and te error message is :

"unable to establish the vpn connection. The vpn server may be unreachable"

They are running v 10 of windows.

I tried different versions of the forticlient (6.4, 6.2) but nothing works.

I used these commands :

diag debug reset   diag debug application fnbamd -1 diag debug appl sslvpn -1 diag debug enable

and the result is :

[185:root:0]total sslvpn policy count: 2 [144:root:0]total sslvpn policy count: 2 [187:root:0]total sslvpn policy count: 2 [186:root:0]total sslvpn policy count: 2 [185:root:0]total sslvpn policy count: 2

It appears that i cant see my connection incoming in the fortigate...

Except some computers works...

Anyone know something about this?

Or anyone already had this issue?

Matthieu