ive got several here and checked out all of mine and the nuts are all good. Not sure what happened on that one.

If you bought it new, I bet Martin would send you a new nut free if you sent them that picture. They also sell nuts on their website I believe. Just make sure you get the right width. When you install it, take extra care to make sure every string is cut the right depth. I know Phil has vids on that as well.