I created a drawing from a part, and I can't get the centerline to show up.  I attached two images.  One is the drawing I'm trying to replicate, with centerlines shown for the curved part.  The other is a screenshot of my problem.  I selected "add centerline" and clicked inside the concave faces, but the centerlines won't appear.  You can see blue pluses where I clicked.  I've done this with several other drawings and the centerlines show up fine, it's just this one.

I have:

-made sure annotations are shown

-checked the layer; there's only one (the default)

-restarted the computer and Solidworks

-combed through every setting (though they haven't changed since the last successful attempt)

-searched these forums and the internet for a solution and I can't see where anybody else has had this problem

*edit* uploaded part and drawing files

*edit again*  went back into part file and fully defined all sketches, still can't add centerline, uploaded latest part and drawing files