This isn’t the usual cry for help, just a solution that may come in handy for anyone using Terabyte Image for Windows.
I only recently started using this program to make system images so I was feeling my way. The first time I backed up C drive to an external USB 3 5TB drive it worked a charm. The next time it failed the Byte-for-Byte validation, and again, and again. Their support responded very quickly with a couple of links to Help pages. One of the first suggestions was to check the USB lead. At this juncture I realized that I had the drive plugged into a USB 3 hub which I use every day without a problem. However, on a whim, I decided to plug the drive into a USB 3 port on the laptop, and it worked perfectly.
David