For good reason. VNX2 has no way to deal with the complex edit steps that would likely exist in a nef file that was edited in CNX2. I'm not sure why anyone who has the ability to edit a nef file in CNX2 would ever want to further edit it in VNX2. It doesn't make any sense to me. If the file needs further editing, why not just re-open it in CNX2 and pick up where you left off with all of CNX2's tools available to you? The good news is that all your CNX2 edits will be represented when viewing the edited file in VNX2.