Passport ultra stuck copying and then progress window has disappeared

I just set up My Passport - Ultra. I chose for it to do a one time back up of all my files (as opposed to scheduling). That was hours ago and it appeared to be stuck at 12%. Then I checked a while later and the window that shows the copying progress has disappeared. Something seems to be happening, but I’m not sure how much it’s copied, if anything. How long is this supposed take? How can I re-do this to ensure it’s copying properly?

How are you copying your files into your unit? A regular copy & paste, or do you use a backup software like WD SmartWare? Progress depends on the connection interface (USB 2.0 or USB 3.0), your computer’s specs, the type of copy process (Direct vs. software), and the total amount of data to be copied.