UO Automap and UOAssist
You cannot use UOAssist with WoD. I believe its a technical issue. You can however use UO Automap. Check to make sure are running version 4.0 of UO Automap. You go to the Castle and sit on Queen Lissar's throne. To calibrate, pull up the calibrate window, and from the "I am in" pulldown menu, choose Britannia. Put zeros in for the coordinates, both latitude and longitude and the degrees. Choose N for latitude and choose W for longitude. You only have to calibrate once per patch.
Dundee's Note: UOA will work with WoD, but you have to buy another licence, since its keyed to your account name/password/whatever which almost certainly are not what they were.