Slow file backups and stalling out

Before creating virtual clients, I reduced my primary client’s files to just one year’s worth, maybe 1/5 of the total data. That one stalled out similarly and I went to the log for that job on the server and see this error:

|04/17/18 16:56 |DEBUG |HT: Copying file: “f:\urbackup\mb-pc\180417-1433.symlink_Pictures\Lightroom\Lightroom Catalog Previews.lrdata\2\2E80\2E80EB8B-D4CF-48CD-B232-74AA03FF6240-23c13717c6330f60706bf1e7c718b3e4.lrprev”|
|04/18/18 08:02 |ERROR |Error getting file metadata. Errorcode: CANNOT_OPEN_FILE (3)|
|04/18/18 08:22 |ERROR |Server admin stopped backup.|

So I wonder if it might be a hardware or filesystem issue?