Now i know the problem, but not the solution
I have an older camera with the same problem. In my case it is caused by the way the camera formats the memory chip (I've forgotten which sort it is, probably SD) - it is larger than what the camera really can handle so it uses an oversized sector size to fix it
Normal sector size is 512 bytes (Note differentiate between sector and cluster and for CDs it really is 4096)
If you do 512/4096 * 8 you get 1 and 980 MB is very close to one GB so you seem to have the same problem
Windows opens my camera (and probably your mp3 player too) because it has an inferior disk handling (oh yes!)
With the wrong sector size you can't be sure that write operations to the disk will be without error - Windows ignores that risk
The bad thing with Linux is that there is no button "Yes, I know the sector size is wrong and 4096 - open it anyway"
I'm stuck with Windows to read my camera
The following advice is not without risk and you have to take that into account - but not so risky that I don't give it
If you can format the mp3 player now, but only if you can, (In Windows perhaps) try the following
Copy the content
Format to normal fat in Mint (must be FAT32)
Try to use it in all places where it is normally used
Hopefully it works ok - if not format it with the nonstandard sector size - remember I told you not to do this unless you could format.
I tried to find if it is possible to use 4096 but I did not manage to write a good enough search phrase