How to troubleshoot a VPN connection drop

How to troubleshoot a VPN connection drop

I have a Windows 8 machine that won't connect to a work VPN (other
machines configured the same* way work fine). The IT dept at work says the
attempt never shows up in the logs. On my computer, it seems to connect
and then suddenly drop that connection. No error messages show up, it just
says its disconnected.
I used Wireshark to capture the an attempted connection on both the
problem computer and a working computer. I'm not very good with raw
network data (like Wireshark provides), but it seems to all work the same
until an unexpected RST packed shuts the entire connection down. Can I use
that data to somehow determine what's causing the unexpected RST and
ultimately the problem? I would be happy to post the log, but I suspect
they have sensitive security information in them...
System Details:
Forigate SSL VPN with Forticlient on the client machine
Windows 8, Asus ZenBook
No certificate or PSK used in connection (user/pass only)
Other VPNs / network services work fine on this computer
*"same" meaning I can't spot the difference, but obviously one works and
one doesn't.