Issue #23248: WRBanneredMareBase01.nif: gap underneath stone wall in mesh
This was originally reported in a placed ref ticket (Issue #23241). I was able to confirm the problem. The particular mesh is very large, but Arthmoor said that we have done fixes for other "megameshes" like it in the past.
The screenshots I linked should give you an idea of where the gap is located. It is very tiny but noticeable if you look close enough.