“Unknown” means the files don’t have tags the Fuze can read. Aftist, Album etc. are not folders but lists made from the tags (electronic labels) in the files. You can deal with the unknowns a number of ways.
You could do Settings/System Settings/Format, which erases everything you have put on, and start anew with your files from WMP.That might be easiest.
Or you could figure out which folders are giving you trouble by going to music and scrolling all the way down, past the first page, to see Folders. That should list the folders, and then the files within them, as if you were looking at them on your computer. Delete duplicates, or ones with bad tags, via your computer.
if you don’t have Folders at the end of the Music list (past Album, Artist, etc.), then you need a firmware update.
Instructions are here.
Use the Manual procedure, which means downloading the All Regions link (1.x or 2.x depending on your hardware), unzipping it onto your desktop, putting the Fuze in MSC mode (Settings/System Settings/USB Mode) and dragging over FuzeA.bin .
Don’t install the Updater, since this is probably the last update.
