Unable to "Flatten-Quilt Deformation" after & "Flatten Quilt".

PTC Creo Parametric 3.0 M080 1. I drew a 2 mm wide ring, and extruded it to a simple cylinder and then "Flatten Quilt" half of it's outer surface. 2. I thicken the quilt to 2 mm, and then "Flatten-Quilt Deformation" as a "Solid Geometry". It prompt "Feature failed to regenerate.....". Can anyone tell me what is wrong with this simple model? And I also attached the snapshot of the whole thing. Thanks!