editor view shows open box, sliced view shows closed box!
Here's a confusing problem. I think I have an object which is an open box. Editor view shows it as expected.
However, slicing seems to think it's a solid box, and puts a top and infill. Which is correct?
Here is the STL file.
Try zipping the STL...
before attaching it.
or right click on the box in editor view, and choose 'Fix Via the Netfab'...
then try slicing again!
Had a look at it using Blenders 3d tool add on and the model has 13 intersecting faces, 43 Zero Faces, 9 Zero Edges and 12 Thin faces.
The main problem area is that front left overhang. In your screen shot it has a section on the player view that has been removed completely in the sliced preview as it is zero thickness and the geometry overlaps in various ways that is giving it issues. This area here mainly but there are others. the geometry doesnt make any sense in this area and when you try and clean it up it effects much more than that area.