Running SlimServer as a service, assigning the Music or Playlist folder to a 
mapped drive letter using the Server Settings web page gives this error message 
(this is not the bug): 

"Oops - "Z:\" doesn't seem to be a valid directory. Try again."

Using the UNC-style path "\\server\folder" does work.

The possibility of a mapped drive letter not working is mentioned in the FAQ, 
even when Slimserver's service has been modified to login as a user account, so 
this error message is not unexpected.

This is the bug: If instead of using Server Settings I use Options -> Set Music 
Library Folder to set the path, I can browse to "Z:\", and this is accepted as a 
valid entry.

Though there is no error message, the invalid path doesn't work, and Slimserver 
will not build the music library index.  There's no clue for the user as to why 
the scan didn't work.

Fix: Selecting an invalid path in Options -> Set Music Library Folder should 
generate the same error message as entering an invalid path in Server Settings.