USB drive used as copy job repo is having input / output error, cannot open the drive in server

Looks like a Windows issue rather than Veeam ​@Bennet .

Try plugging the drive to another USB port if you have one and see.  Also run a chkdsk on the drive.  This is not Veeam as Shane mentioned, it is a Windows issue.

from my understanding based of the screen shoot provided, it’s my opinion that its An I/O (Input/Output) device error basically means Windows tried to read from or write to the drive, but the drive didn’t respond properly. It’s not a permissions issue or a bad path — it usually points to a problem communicating with the hardware.

Since the U: drive is coming from a USB‑connected disk , this usually means something is wrong somewhere in the USB chain — the disk itself, the enclosure, the cable, or the USB controller — rather than an issue with Windows itself.

Check this drive on another computer as well. If you’re unable to view it’s contents still, it points to it being an issue with the external drive, or like Jason said, the disk, enclosure or cable.

Try shutting down your server.  Unplugging the USB drive.  Turning it back on and letting it completely boot up.  Then plug the drive back in and see if you can see everything on it.   USB drives have a tendency to fail without warning.