So yeah, I have a flash drive that has a 16 GB capacity. When I copy a single file to my flash drive, it works. When I copy a folder, it works aswell, until I plug the flash drive off my computer, after doing that, if I connect it to my pc or another one, it shows only an empty folder or more depending on how many I actually tried to copy. What could be wrong ? And I've double checked and the files ARE there before I remove the flash drive. Also, I do remove it safely via the hardware manager.