Why won't my model run?

Problems can occur when a model has too many shells. "Too many" is subjective, but start thinking about this if the number of shells is higher than about 5000.

Pedestals are meshed into a fixed number of shells. So if small pedestals are defined, this will lead to a large number of shells within the footprint of the pedestals. And part of the magic of this module is that the meshing algorithm ensures that the meshes under the pedestals are tied in with the mesh in the surrounding area of the footing. So having small pedestals results in many tiny shells in the footing around all pedestals.

Working outward from there, the program has built-in parameters to ensure mesh quality. These control how rapidly the size of the shells can change, as it attempts to conform to the "target" shell size for the footing. So small pedestals, and closely located pedestals can have a significant impact on the total number of shells in a model.