Afternoon all. I am in the process of implementing an Always On before Windows Logon VPN for a customer and not having much luck. I am struggling to get the Machine Tunnel to establish. I have been over the configuration a few times and cannot see anything wrong. I have the same configuration in my lab which is working fine. Both the customer and my ADC are running firmware 13.0-79.64 and we have tried a few different versions of the Plug-in. If the customer logs on to the PC they are able to connect to the VPN and establish the user based tunnel so only an issue with the machine tunnel. I have run a trace again both environments to compare the differences and the only one I can see is the customer environment has an HTTP 1.1 Server 500 error which is then followed by a Close Notify packet (see screenshot). This is after the initial establishment with the main AO URL which completes fine. I think the certificate authentication seems to be working OK as the ADC is stamping a Cookie on the session which is then used for subsequent packets but not sure if it would do this even if the cert auth failed. Can anyone provide some advice on the best way to troubleshoot the issue please? I have hit a brickwall.