A co-worker recently came to me with the part model that I've attached here. He was having problems because he would apply a material to the model and the display wouldn't change. It always appeared black. He would open a sketch on a face and it was difficult to see fully defined sketch geometry because the part was pure black.
I looked at all the usual suspects and, for the life of me, couldn't get a color/texture/appearance to show at all!
And then I noticed - there were absolutely NO Display States present in the model. None, nada, zip, zilch! How is that possible?
Once I discovered this, I was able to RMB in the display state manager and add a new one and that cured all our woes but I was flabbergasted as to how it could be that way to begin with. Since then, I've tried, to no avail, to create a part with no display states, delete any/all display states, etc. I just can't.
So, I present this more as an oddity than a bona fide question but I'd be interested in hearing your thoughts.