Details
After importing curves into NX, the curves are extruded into a solid body. When attempting to add edge blends, none of the edges are selectable.
Solution
The reason that the edges cannot be selected is because the solid body is a Convergent body. This was the result of the curves that were imported into NX that resulted in 1 degree splines.
There is a Modeling Preference setting called "Treat Degree 1 Spline as polyline". If the curve string that is selected for an extrude has at least one,1 degree spline with this preference setting toggled ON the resultant body is a Convergent Body. With that preference setting toggled OFF, the result is a Solid Body.
Hardware/Software Configuration
Platform: INTL64
OS: window
OS Version: 764
Product: NX
Application: DESIGN
Version: V12.0
Function: FEATURE_MODEL
Ref: 001-9054062