Edge material prioritized over outside surface material

[DangCad]

In my model, there is one corner where the edge surface material is visible instead, and I can't figure out why. See screenshots below, two where the walls selected if it helps. 

DangCad,

I have edited this post to show your images.

Rather than saving as JPG files and attaching, simply copy and paste the screen shot directly into the post.

That way readers don't have to open the images.

Barry - moderator.

[Rico · Accepted solution]

You need to select this option:

I don't remember what it is in english but it should be self-explanatory.

Rico 

[DangCad]

Perfect! That solved it, never seen that option before. Thanks!