Users cannot see the NX assembly constraints in a couple NX assemblies. The constraints are listed in the Constraint Navigator but not displayable in the graphics window.
There's a toggle for "Display constraints in Graphics window" to control the display of the constraints that is located in the Constraints Navigator and in the Assemblies Navigator.
In the Assemblies Navigator select "Constraints" using MB3, the display options for "Display Constraints in Graphics window" and "Display Suppressed Constraints in Graphics Window" will be listed.