The tool path is stored inside the operation. Note you can "right-click on the operation" -> Toolpath -> Delete
So while you may not be able to generate the operation, you can replay/post process it.
The real issue is why the drive geometry goes missing.
I would suggest reporting this issue to GTAC or your VAR, to figure out why.
NOTE: Assuming the part (model) geometry is in a separate part file (a component of the NC program part), please verify you are opening the same model component in both versions of NX. (i.e. check your load options, or open the modle geometry component FIRST, then the NC program...)
Ken Akerboom Sr CAx Systems Engr, Moog, Inc.
Production: NX10.0.3.5 MP16/TC11.2 I'd rather be e-steamed than e-diseaseled