I just got a SanDisk Clip Sport. I placed a MicroSD card in it and loaded it up with MP3 and AAC (.m4a) music files. They play fine and the info tags show up fine. But I simply cannot get a playlist to work with this device. I keep my music organized in iTunes (v. 12.4.0 119) on my Mac. I used the File>Library>Export Playlist command to export my desired playlist as a .M3U file. I placed this file in a folder, along with all of the MP3 and AAC files for the songs that the playlist references, in the same folder and then I placed that folder in the Music folder on the card. (This folder shows up as Music when viewed in the Finder on my Mac but it is labeled as Songs in the menu structure on the Clip Sport.)
When I open the playlist on my Clip Sport, it simply says “Empty”. I went back through every song and album title contained in the playlist and removed all of the following special characters: ? #  /
Then I formatted the card and exported the music files and the playlist file again. Still no luck, the playlist comes up as “Empty”.
Any advice on what I should do?