The point at where the measurement is taken is a bit of a mystery (though consistent for a given design - as in, for a particular design, it seems to scan at the same place every time you run it.
Some designs it scans at an outer boundary. Some it wants to hit right in the middle of an engrave area.
The time or two I’ve received that error is because part of my design was placed just off of the material and it chose that spot to scan (which was ok in that case - saved me a miscut).
Have you watched the scan process? Is it hitting a hole or off of the material somewhere?
Edit to add: I assume that it scanned the QR code and identified the material, or that you selected the material manually?