I designed an object in 3ds Max, did an STL Check, and there were NO errors. When I exported my model and uploaded it here it said that I had non-manifold errors. To check that, I opened my STL file in Blender (Um...confusing coming from Max!), and it basically reported that ALL of my edges were open. Again, I did an STL check and it reported that all is well. Another thing...it's importing HUGE objects! I have my system units to 1 unit = 1mm. This particular model is about 9 inches wide and long, and about 1 inch tall (it's a display base for another model). I can't even figure out how large the base is in Blender, but it's HUGE! Oh, woe-is-me, but what am I doing so wrong? This is 3ds Max 2010, but the same thing occurred to me a couple of years ago in my older version 6. Any ideas?