Forticlient VPN connection fails consistently at 80% with error (-12)

[zappity]

I'm having a problem with Forticlient trying to connect to a company VPN. Every time it fails while showing 80% finished with the same error: "Unable to logon to the server. Your username or password may not be configured properly for this connection. (-12)" The thing is, the username and password are correct. If I deliberately mistype the password, it fails at 48% and I instead get a different error "Permission denied. (-455)" The only clue I have is between the last time I was able to log on without problems and when the logon started failing, a Windows Update was installed--around Oct. 2. After that the company reset my password, and it worked briefly again, but then started giving me the error again. Rolling back the Windows Update wouldn't work--Windows kept failing to restore the pre-update system. Reinstalling, upgrading, downgrading, reinstalling Forticlient didn't work either--still get the error. Switching to an older hard drive that had an older set of Windows Updates did work (I tested it with Windows Updates through about June or July 2018, and left everything after that uninstalled), but going that route will mean I have to boot from that drive instead of my main system drive every time I need to use the VPN. Any ideas as to what could have triggered this issue and what the solution is? I'm on Windows 7 64 Pro, currently using Forticlient 5.6.0.1075, though like I said the specific version doesn't seem to be related to the problem, as none would work on this system drive, while both the older and the newer versions worked on the other drive without the recent Windows Updates. 

[FirewallNoob]

I just had this issue - are you using proper case for your username?

USername vs. username?

How it's setup and displays in the fortigate is how it should be entered in the VPN client

[andrew1]

see this: [link]https://forum.fortinet.com/tm.aspx?m=145662[/link]

[rlsenthilk]

Please Downgrade the Forticlient.. use 6.0.3 version