I just figured out how to do this as well. Help says you can't delete your state return if you've already paid but that was incorrect. I chose start over for state without entering any info. I then clicked Home\State and "Pickup where you left off". That's where it gave me the option to Delete NC State Return....and I was able to file Federal without this issue.
So it's clearly a state issue (i.e. NC is not ready to accept state returns yet).
