Can't extrude

I can’t extrude this series of faces. Why?

4Runner.blend (800.1 KB)

That object is quite a mess: You have one huge n-gon overlapping the other polygons. So, when you select everything and try to extrude, Blender can’t fathom what you are trying to do…

Delete the n-gon, then extrude. Or select everything but the n-gon and extrude.

The way you can see and find it is to

  • look for face indicators in face select mode that are out of place (top)
  • bad artifacts in solid viewmode, usually caused by overlapping geometry (middle)

There are also few other concave n-gons you might want to get rid of (bottom, marked orange/brown)

Thanks so much! My student thanks you as well!