Quirk report:
The client cannot handle non-standard english characters. So if you are trying to open a folder with (for example) an album with Spanish language songs with accents and special characters you will not be able to open the folder. Also, if you are trying to access an artist folder with a special character (like, I'm guessing Mötley Crüe) you will not be able to even access the artist folder.
The quick solution is obvious: just rename a couple files and you are good to go.