I formatted the hard drive on the player, not the one on the computer. Before, it worked fine. I don't know why it doesn't work anymore for 2 days. First, it told me that I wasn't allowed to transfer any new files on the player. Then, I formatted the player, reinstall SonicStage, with a new library. Now, every time I connect the player, SonicStage is searching for tracks that would have been deleted... At 66%, it stops, gives an error (The information about rights (MAC) are incorrect ) and then, it restarts... There are some files in the library, but the player is empty. So, I can't try to transfer a WAV or WMA file because it is still searching for these tracks... I don't understand