Well we should have tested on a closed figure, that was the problem. When you run Check for Updates in the morning, follow this procedure.
1) Set the surface to no display so you can pick FeatureLine?
2) Start the Figure Grade Elevations tool.
3) Select the FeatureLine (anywhere).
4) Enter P for Plane (if it's not already the default).
5) Press enter to use the figure beginning.
6) Press enter to use the figure ending.
7) Pick the plane start point (X=369795.789 Y=667605.239 Z=343.290)
8) Pick the plane direction point (X=369793.138 Y=667457.263 Z=343.290)
9) Enter the desired percent slope (-1.0) ?