I had about a dozen music cd's in a dozen different folders on a thumb
drive.
Then I started to copy two more audio folders to that drive.
While there were being copied, to save time, I decided to delete the music
folders.
The result was the individual songs were not there but there folders were
in the trash bin and I could not empty the bin.
It is on a FAT32 thumb drive.

I won't try that again.