Where is NONE in Nationality?
 

I thought there was a NONE for Nationality, especially for second nationality

I checked OOTP 25 and (unknown) is in the list at the top, but still missing in OOTP26.

To make the second nationality go away, just assign the same as the first one. I agree that having a "none" (ideally at the top of the dropdown) would be much easier.

We'll fix this up for the next update.