Hi Elroy,

Mesh defines the resolution of the terrain. As a standard FSX has 38m terrain resolution in the US and Europe. If you imagine a horizontal grid, there is a point every 38 meters, at which the altitude is defined. When you use a mesh with higher resolution (19, 10 or 5 meters) you will be able to see much more detail in the terrain (cliffs, narrow valeys etc.)

Mesh is handled differently by FSX than other Scenery addons. For a certain region FSX will always display the mesh with the highest resolution that is activated in the scenery library. There is no need to give the mesh a higher priority than other library entries.

I don't know about the order in which the files of this specific addon have to be installed. I would guess that you first install the different parts (different regions) and than the batches, which may solves some bugs (etc. gaps in the terrain) - but I don't know the addon. Maybe someone, who knows it can comment on this.