Details
Have you ever experienced a strange behavior in your part where you are unable to see curves after using certain command like Stretch Curve or select the edge or end point at a particular location of your part?
NX behaves like there is a clipping plane at a particular corner of the part.
Solution
The problem could cause by Section Clipping Plane.
You can try either 2 options below to fix the problem:
1) Toggle Off the "Clip Section" button which is located in the View ribbon or Menu --> View --> Section --> Clip Section.
Or:
2) Launch "Edit Section" from the 2 locations mentioned above and move the current clipping plane to a new distance either dragging the vector or enter a new distance in the dialog.
Hardware/Software Configuration
Platform: all
OS: n/a
OS Version: n/a
Product: NX
Application: SYSENG
Version: V9.0.3
Function: DISPLAY
Ref: 001-8947775