If you are having difficulty creating a New Scan on a given workpiece, or if you notice that Origin is failing to register dominoes on the screen during a scan, you may be experiencing veiling from your workpiece itself.
This means that light is bouncing off your workpiece in such a way as to make it difficult for Origin to register the contrast between the workpiece and the dominoes on the tape you have laid down.
Often, this issue can be resolved by either adjusting your lighting setup or moving your workspace itself and then creating a New Scan.