Hi klego - that's most likely because p3d.in is having difficulty processing complex n-gons.

An n-gon is a polygon with more than 3 or 4 sides in it, and if you export a model like you've got there using n-gons there the polygon on the top will be a pretty big non-convex n-gon and it is not too unusual for some programs to have problems handling those.

When you export out of MoI, try switching from "Output: N-gons" to "Output: Quads & Triangles" or "Triangles only" and that should probably avoid the problem in p3d.in :



- Michael