Need help with big terrain print

[Martin_au]

Looks like most of the issue is the STL file itself. Lots of non-manifold edges and other issues. What's the original file in? Sketchup? Is this stl a direct export from that program?

[FiftySeven]

Yeah, I do not know how to exactly fix the 3d model, I modelled it in bim program(archicad). I do not exactly know what are you reffering exactly to? because I was very satisfied with the terrain print, so the only real problem is the archeology walls I presume? Is there any shortcut way of fixing this, or do I need to remodel the whole thing? Although i wouldnt really know how to model it diferently..

But basically you think there is nothing wrong with the settings, the only thing that is causing issues is the model itself?