I sent a finish surface file generated in c3d 2014 to a surveyor, who is running c3d 2016. The probem is that none of the contours actually show up in 2016. The contour labels appear, and if the label line is dragged around the labels will update as the cross the (invisible) contours. Displaying TIN lines show that the surface is there -- style is set to display major and minor contours, and the layers assigned to the contours is turned on and thawed.
My fall back -- will be to extract all the contours from the surface as lwplines at elevation, and send them as a separate file. But I would like to understand WTF is going on between 2014 and 2016.
Any ideas?