Hi Pilou, the problem here is that the object isn't a completely closed solid, even though it looks like it is.

There appears to be some problem in join where some edges did not get glued together, I'll see if I can find out why.

The UV unwrapping is normal for MoI's current output. MoI currently outputs UV coordinates where each surface has UV coordinates that span the entire UV square. So what you are seeing there are the meshes for each different surface in that object stacked on top of each other.

At some point in the future I should be able to update this so that each surface gets a separate UV square instead of only all of them on top of each other, but I won't be able to do that for V1.

- Michael