Join the club! This happens on my FIIO X3 and my Galaxy S5. I have tried: formatting in the device, using the USB mode, formatting in both PC and a MAC as FAT, exFAT. I've tried using a card reader and the same thing always happens. A limited amount of music is recognizable, but whole folders "copy", but then nothing is in them although the card registers the amount of data when going to properties. Very frustrating! I have scoured the net and not found a single solution. The other solution, get rid of the Android devices and switch to Apple, which is what I should have done. You can't imagine the hours I've spent on this just get take advantage of being able to use a card. Even though the Apple environment is very controlling, at least it works! I have a FIIO X3 for sale going cheap!