I've been using my mp4 player for a good while now, but a few weeks back it died on me, kind of. The player turns on perfectly, and I can navigate the menus, but I cannot access any of my files. Whenever I try to, it gives me a message, "Disk Error!", for some strange reason. I took it to work once and I believe that I forgot to select "safely disconnect hardware" when I unplugged it. Of course such things are random, as I'd forgotten to do that many other times with no repercussions. Here's some pictures:
My lovely mp4 player, just 60 euro with shipping from an ebay seller.
The main menu, highlighting the music option.
The disk error message.
If anyone has any idea of what to do, please help me out

I have not tried to install new firmware nor mess with the OS of the player, just so you know. Thanks in advance!