If you get this error while trying to connect to SSL VPN, this could be because there was an improper log out in the previous session and some of the processes did not close properly. Verify if any of the SSL VPN processes are running. For more information on how to verify, see Section 41.4, Verifying SSL VPN Components.
If this error occurs, manually kill the process if you are an admin or a root user of the machine. If you are a non-admin or non-root user of the machine, then restart the machine.