While the copy is trying to run, Open Task Manager, go to Performance and look at the "active time" and "disk transfers rates" on your drives. If the active time is high on one of the drives but there's not actual data being transferred that suggests you have a significant issue - probably a failing Hard Drive.
Tools like HD Tune can look at SMART data which can give you further clues to a drive's health.
If you have important data on either of those disks (particularly the HDD), I'd be taking a backup right now before I did any further testing (and particularly anything stressful like sustained copies or low level error scans).
It might turn out not to be the disks, but if it is, then small errors can quickly escalate into a bricked...