I recently faced a strange issue after configuring and trying to connect to an SSL VPN hosted on a DrayTek Router.  I initially updated the DrayTek Smart VPN Client to the latest release 5.6.3 which did not resolve the issue.  I then decided to change the SSL VPN Users password and identified that the below error was a result of using the £ symbol in the SSL VPN Users password.  Once I removed the £ symbol from the password I was able to connect without error.  It’s possible that other special characters may cause the same problem so if you also encounter this error I would initially suggest simplifying your password for testing purposes.