Had this issue on my 2013 Goldwing, had to change all the Windows Media formated audio files to MP3, drove me crazy for a little bit. I had loaded 50 or 60 songs from various CDs, when I tried it out only 10 or so would play, checked the flash drive on my computer, all the files were there, but seems that those 10 were formated as MP3 right off the CD, the others were in the Windows Media format, converted them and it is all good now.