Answer:
If a cell closed on all sides is detected in the structural model, it can be used for the load application. However, if the desired load range is not completely enclosed by members, the cell is not recognized by the load generator.
The "Nodes on virtual lines" function allows you to define the corner nodes of the load area manually, and thus clearly define the cell area. The cell defined in this way can then be selected as usual by using the pick function of the individual cell nodes.
