(Optional) Users of non-US keyboards should see these steps .
In Vine Server's Preferences > Device setting, make sure the Keyboard Layout option is set to Current Keyboard.
In System Preferences > International > Input Menu, enable the Unicode Hex Input keyboard, and select it whenever you connect using Vine-Jaadu Server. It supports non-US keyboard layouts, and also supports special characters (e.g. diacritics and umlauts).