Maya Subdiv surfaces


I’m getting a fringe on different SubDiv (Cat-Clark) crease settings. The example below uses Emissive values only to illustrate the fringe. I included an example with No SubDiv but soft edges to exaggerate the effect.
Any advice on workarounds?



Could you attach a small scene reproducing the issue?
I am not sure how to reproduce it myself.




I hope the attached file is clear.
The Cube on the right, which has no subdiv but has edge smoothing, is the simplest example I guess.
Subdiv (39.1 KB)
screengrab below

Also while making the sample file I noticed appleseed disregards shadow casting/recieving preferences. Illustrated on the lowest image.
under Render Stats, in object Shape Tab, the cast shadows & recieve shadows check boxes have no effect (theyre the only ones I’ve tried so far).