Edit: I typed all of the below and failed to mention - uninstalling KB2693643 did in fact resolve the issue. Thanks u/QuietThunder2014 
I wanted to share this in case it had not already been shared and anyone else runs into this issue and, like me, exhausted all of their troubleshooting efforts.
A member of my IT team started experiencing issues connecting to VPN (SSL) with FortiClient. The progress would make it to 98% then bounce back, retry a few times and then fail.
I checked the usual culprits, a thorough check through EMS, the settings on both the client and the FortiGate, compatibility issues etc. Then I started digging through FortiAnalyzer VPN logs and packet tracersā¦nothing seemed to be pointing to the culprit.
At one point, from the FortiClient, I identified this error:
info sslvpn FortiSslvpn: 22696: Did not find interface for local_gwy 25ed170a
There were plenty of āsolutionsā I found in other Reddit posts, Microsoft forums even, but none worked. Everything from disabling IPv6 in the interfacesā settings toā¦well if you made it to this post you probably already know and like me, had to keep looking.
Finally, I came across this post: FortiClient SSLVPN Windows 11 routes problem - Fortinet Community
Now, I have Windows 10 with RSAT installed, but not through this update. Furthermore, KB2693643 is supposedly for W10, yet it came as an update on my coworkerās W11 machine. They hadnāt enabled RSAT in Windows Features nor downloaded to this machine yet, so we were unaware it was there. Sure enough however, once they uninstalled this update the VPN connection via their FortiClient worked.
Iām not sure if this has been shared already, but I wanted to make sure that if anyone else is experiencing this issue they have all available troubleshooting resources at their disposal. Hopefully Fortinet identifies this and finds a solution because even with FortiClient 7.0.7.0345 this is happening (downloaded from Fortinet yesterday).
