Render error with viewport subdivision

[DPGrafik]

I have a strange error, whenever i enable viewport subdivision on a mesh, the surface renders black. Its a refractive surface. If i go back to level 1 it renders fine

Subdiv level 1



Subdiv level 3


anyone else had the same issue?

[vlado]

Works fine here in a simple test. Can you get us just the relevant part of the scene to vraymaya@chaosgroup.com so that we can look at it?

Best regards,
Vlado