So I'm trying to safely remove this USB drive, because when I don't it does not work properly. When I go on Nautilus and try to eject it, I get this error message:

Error ejecting: eject exited with exit code 1: eject: unable to eject, last error: Invalid argument

And when I try to safely remove it via Nautilus or Disk Utility:

Error detaching: helper exited with exit code 1: Detaching device /dev/sdb

USB device: /sys/devices/pci0000:00/0000:00:12.0/usb3/3-1)

SYNCHRONIZE CACHE: FAILED: No such file or directory

(Continuing despite SYNCHRONIZE CACHE failure.)

STOP UNIT: FAILED: No such file or directory

Doing a file system check on Disk Utility returns File system is clean.. Trying to unmount it via terminal returns this:

~sudo eject /dev/sdb

eject: unable to eject, last error: Invalid argument

I've tried to unmount it on Windows (dual boot system), but I simply got an error message saying that it was unable to eject it. No programs running or anything.