Ok. The problem was in the "forest grama 2" object. I have found several issues:
- The "Surface Area" is on, so Forest is scattering items along the full terrain. Then, all items are removed because the "Rectangle002" exclude. This is pretty inefficient. Just turn "off" the Surface Area to get the same result.
- The "via central" area is the main problem. Although Forest can exclude by a geometry, there are certain limits in the mesh size. In this case, the excluding object has more than 800k faces... this is too much, and the excluding process takes forever. Instead a mesh, i suggest to use some splines here.
To load the scene, just merge all objects in a new file (except "forest grama 2" obviously).