Answer:
If member loads are generated from an area load, extremely small concentrated loads may result, depending on the nature of the surfaces. If these are too small to be displayed with the number of decimal places in the output, the load is rounded to the value 0.
Image 01 illustrates this effect.
In the load wizard, there is a "Smooth concentrated load" check box. If it is selected, such concentrated loads are converted into variable loads. Image 02 shows this option in the load wizard "Member Load from Area Load".
