No no no! The cause of hidden vertexes is accidental pressing of shortcut Alt+I while you are in subobject vertex level. The solution is simple: go to that level again and just press Alt+U. It is max's feature. When you are on subobj level you can hide (and show) unselected vertexes/faces/objects. Have a nice day friends!
I'm having a similar problem, but I can't even select the vertices by clicking and dragging where they should be. Oddly, I get one vertex that shows up and allows me to select it. I know the other vertices are there because I can select all the faces and then go to vertex mode, but that doesn't help when trying to modify…
I have no idea what causes it, but I know how to fix it (most of the time) Select your object, go into Vertex mode, and hit "unhide all" like you would with polies. WHY you can hide vertices, I don't understand.
It happens to me sometimes, it seems like it's resetting the vertex draw size (default is 4 pixels or something), it seems to go back to 1px because I can still sometimes see the verts glittering in and out of view under the wireframe. The way I always seem to be able to fix this is by selecting all vertices then go to…