I may be missing something, but I have a "hole" and I need to fill it. The find and fill holes items didn't seem to detect this as a hole. I made sure that all of the corners were collapsed and welded to that it was a continuous edge. I tried selecting sets of 3 or 4 verts that would make a normal tri or quad, but in vert mode, I couldn't find a way to create a face and if I changes to face mode, my vert selections disappeared. I Did try Fill Hole and Connect Vertices. Connect Vertices said "(3 or 4) vertices connected" but I could see no change in the geometry. On the other hand, Fill Hole returns "Too few unique points selected": Shouldn't 3 (or 4) vertices define a face? I tried this on both the tri indicated here and a quad next to it. Didn't work. The only thing I could thing of was a bit silly. I extruded an edge: and then I collapsed the vertices: There's gotta be a better way! What am I missing?