Good point. Snapped a picture and here it is. Its a 90deg corner. I am following the beigher paint around but you can see(not the best pic) that the ceiling slopes in two directions and hits that corner. Maybe I do need some kind of transition but thought there would be a way around it.
Thanks for the help.
Now I see. Thanks for the picture. The end result is that your crown will not meet the ceiling. You will have open top crown.