Adding music fails when a dash "-" is in the folder name

Not anymore.

The whole music import has been rewritten. It now uses musicbrainz.org as its primary source of metadata (with added bells and whistles from other sources, like allmusic.com and last.fm).

You now always need to have the principal structure of
music / album artist / album title / tracks

A dash may be interpreted as separation of artist and album title.