Open your servuo folder- then open Config folder-look for Datapath and set inside to your game client
You will see this
DataPath config
# Uncomment this line and set it to the path of the client files to set a
# custom data path. Otherwise ServUO will look for the client in the default
# Windows installation directories. Note that this is *required* when running
# on non-Windows systems.
CustomPath=C:\Program Files\Electronic Arts\Ultima Online Classic<<<<<<___ remove the #in front-add the path to your game client
# If true all data paths other than CustomPath will be ignored.
IgnoreStandardPaths=False