Yep looks like the inner ring has a ring of polys that's duplicated, flipped and welded in the center. You could delete the inner rings, and use bridge to close the gap.
I looked at the file. I have no idea how you did it, but you have a giant duplicate polygon group that was basically generated in the center-most ring, just underneath the one you would expect to see. To see it (and fix this mesh), go into Border mode and drag select around the very center inner-most area. You will select…