Well, I know that what I'm about to assert isn't very cyber-savvy, although I am fairly so. I have a 13 year old Dell Inspiron 530 desktop which I share with my wife. I had noticed odd behavior of the View NX2 program after she logs off her user sector of the machine, and I log back on. If I access View NX2 and open a folder containing multiple .NEF files which I want to convert to .TIF files, there will be a few seemingly random .TIF files that will halt the conversion process, prompting this Error dialog: "You cannot apply this operation to unsupported files. Please re-select files and try again."
I can state that if you re-boot the system, View NX2 behaves flawlessly, again, until she logs on to take care of her business on the machine.
I don't know why, but it's probably because something she does in some other program on the machine changed some registry value in the View NX2 program. She does not access View NX2 and has never used it.
Just one of those inexplicable Windows glitches.