When you have a Starter license, Diamonds will check the number of mesh nodes when you start the elastic analysis . If your model has 2500 mesh nodes (or lower), the model will calculate. If your model has more than 2500 mesh nodes you’ll get a warning. So while defining the geometry and the loads, no notification or warning is given when passing the maximum number of mesh nodes.
What you can do with 2500 mesh nodes highly depends on the choosen mesh size. Below are some example structures with 2400-2500 mesh nodes and an acceptable mesh (not too fine and not too course).
Bar structures
For bar structures, 2500 mesh nodes corresponds to approximately 300 bars.
2D Bars license
3D Bars license
Plate structures
For plate structure, there is no equivalent in number of plates. It depends on the size of the plates and the choosen mesh.
2D Slabs license
3D Structures license 
In your own Diamonds model
In your own Diamonds model, the number of mesh nodes is displayed at the elastic analysis. In the image below, there are 221 mesh nodes.