I tried to use the newest ViewerX with the newest SecureVNC-DSM-Plugin and the newest UltraVNC Server.
It gets an initial connection, however then it asks for a password in a dialog box. The connection is stabled completely after the password is typed in.
Neither the ISmartCodeVNCViewer3:assWord field nor the IScVxUltraSecurity_SecureVNC:assphrase property work. They are ignored completely.
For the SecureVNC connection the latter should be used, because it allows for passwords longer than 8 characters.

PS: I tried to get in contact with ticket OGZ-895-20142, but didn't get a reply